This was CNBC's live blog tracking developments on the war in Ukraine.
Ukraine President Volodymyr Zelenskyy's visit to Washington has been hailed as a historic, diplomatic success and it's sure to be one that Kyiv hopes will boost the chances of ongoing financial and military support for Ukraine as the war continues.
U.S. President Joe Biden and Zelenskyy met at the White House for a bilateral meeting and at a joint press conference that followed, Biden pledged to help the Ukrainian leader for "as long as it takes."
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The Ukrainian leader then gave a rousing and historic 32-minute address to U.S. lawmakers at the Capitol building in Washington on Wednesday night.
"Against all odds and doom and gloom scenarios, Ukraine didn't fall. Ukraine is alive and kicking," Zelenskyy said to a loud round of applause and several standing ovations.
"The battle is not only for life, freedom and security of Ukrainians or any other nation which Russia attempts to conquer," he said, "the struggle will define in what world our children and grandchildren will live."
Zelenskyy assured Americans that their money isn't being wasted in Ukraine, saying its soldiers know perfectly well how to operate complex U.S. weapons systems and planes.
Andriy Yermak, the head of Ukraine's presidential office, said on Telegram that the meeting between the two presidents is "historic." "A great victory is ahead," he added.
Germany arrests intelligence service employee suspected of spying for Russia
German authorities said they had arrested an employee of its foreign intelligence service (BND) on suspicion of sharing state secrets with Russia this year and thereby committing treason.
Police arrested the suspect, a German citizen identified as Carsten L., on Wednesday in Berlin, the federal prosecutors office said. It said police also raided his flat and workplace as well as those of another person.
"The accused is suspected of state treason," federal prosecutors said in a statement. "In 2022, he shared information that he came by in the course of his work with a Russian intelligence agency. The content is considered a state secret."
In a separate statement, the BND said the employee had been placed in pre-trial detention and searches at two of its offices had been carried out.
German authorities have warned of likely heightened Russian spying given the Kremlin's stand-off with the West over its invasion of Ukraine. The German government expelled 40 Russian "spies" in April, according to the domestic intelligence agency.
Pelosi stands alongside Ukrainian flag presented by Zelenskyy
U.S. House Speaker Nancy Pelosi stands alongside a Ukrainian flag presented to her by Ukrainian President Volodymyr Zelenskyy during his trip to Washington, D.C.
— Jacob Pramuk
Russia’s Wagner received arms from North Korea, White House says
The White House said that the Wagner Group, a private Russian military company, has taken delivery of an arms shipment from North Korea to help bolster its forces as it fights side-by-side with Russian troops in Ukraine.
White House National Security Council spokesman John Kirby said U.S. intelligence officials determined that North Korea completed an initial arms shipment that included rockets and missiles last month.
"We assess that the amount of material delivered to Wagner will not change battlefield dynamics in Ukraine," Kirby said. "But we're certainly concerned that North Korea is planning to deliver more military equipment."
The White House has expressed alarm about Wagner's growing involvement in the war as it has been particularly active in the eastern Donbas region. Kirby said in certain instances Russian military officials have even been "subordinate to Wagner's command."
— Associated Press
Putin says Russia wants end to war in Ukraine
President Vladimir Putin said that Russia wants an end to the war in Ukraine and that this would inevitably involve a diplomatic solution.
Putin made the comments a day after U.S. President Joe Biden hosted Ukrainian President Volodymyr Zelenskiy in the White House and promised him continued and unwavering U.S. support.
"Our goal is not to spin the flywheel of military conflict, but, on the contrary, to end this war," Putin said. "We will strive for an end to this, and the sooner the better, of course."
White House spokesman John Kirby said Putin has "shown absolutely zero indication that he's willing to negotiate" an end to the war, which began when Moscow sent troops into Ukraine on Feb. 24.
"Quite the contrary," Kirby told reporters during an online briefing. "Everything he (Putin) is doing on the ground and in the air bespeaks a man who wants to continue to visit violence upon the Ukrainian people" and "escalate the war."
U.S. sanctions Russian naval entities over attacks on Ukrainian ports
The U.S. sanctioned 10 Russian naval entities over attacks on Ukrainian ports.
The move is the latest the Biden administration has taken to try to punish Russia for its invasion of Ukraine.
"In the wake of Russian naval operations against Ukrainian ports, including those that are providing much-needed food and grain to the world, the United States today is imposing sanctions on Russian naval entities," U.S. Secretary of State Antony Blinken said in a statement.
— Jacob Pramuk
Zelenskyy says he is leaving the U.S. with 'good results'
Ukrainian President Volodymyr Zelenskyy said he was leaving Washington, D.C. after achieving "good results" during historic stops at the White House and U.S. Congress.
"We are returning from Washington. We are leaving with good results. The results that will really help us," he said on his Telegram page, according to an NBC News translation.
He said his country will receive financial support from the U.S., and pointed to "other agreements" that he would elaborate on later.
"I thank President Biden for his help, his international leadership, and for his determination to win," he said. "I thank the Congress of the United States — both houses, both parties, all those who support Ukraine, all those who want victory as much as we all do."
— Jacob Pramuk
Germany nationalizes gas supplier Uniper after EU approval
he German government said that it has nationalized energy company Uniper after the European Union gave its blessing for it to rescue the gas supplier.
The government announced its plan to nationalize Uniper in September, expanding state intervention in the energy sector to prevent a shortage resulting from Russia's war in Ukraine. The deal built on an initial rescue package agreed in July and features a capital increase of 8 billion euros ($8.5 billion) that Germany is financing.
Uniper's existing shareholders approved the measures on Monday. The EU's executive Commission gave its conditional approval on Tuesday. The government is obliged to reduce its stake to 25% plus one share by 2028, a deadline that can only be extended with the Commission's approval.
Germany's finance and economy ministries said Thursday that the government has now taken a stake of some 99% in the company. Uniper's existing management remains in place.
— Associated Press
Brittney Griner asks fans to write to American detainee Paul Whelan in emotional letter
WNBA Star Brittney Griner encouraged fans who supported her during her nearly 10-month-long detainment in Russia to reach out to American detainee Paul Whelan.
"My family's whole and now, thanks to you, we are fortunate to get to spend the holidays together," Griner wrote in a letter posted to her Instagram page. "However, there remain too many families with loved ones wrongfully detained."
"Those families stood alongside you all who supported the WeAreBG Campaign to bring me home and it's our turn to support them," she added.
Griner was freed from a Russian penal colony earlier this month after the Biden administration negotiated a prisoner swap with Russia. She finished the letter by asking fans to join her in writing to Whelan, who has been in detention for nearly four years on an espionage conviction. The U.S. government has said Whelan's conviction is without merit.
IAEA discusses Ukraine nuclear plant protections with Russia
The head of the U.N. nuclear watchdog met in Moscow with officials from Russia's military and state atomic energy company as he pursues a long-running drive to set up a protection zone around a Russian-occupied nuclear power plant in Ukraine.
In Ukraine, the Moscow-installed leader of the partially occupied eastern Donetsk region reported that Ukrainian shelling of a hotel in the Russian-controlled city of Donetsk killed two people and wounded several others, including a former Russian deputy prime minister.
Russian company Rosatom described the talks on measures needed to safeguard Ukraine's Zaporizhzhia Nuclear Power Plant and the surrounding region as "substantive, useful and frank." International Atomic Energy Agency Director General Rafael Grossi indicated that more negotiations were needed after "another round of necessary discussions."
"It's key that the zone focuses solely on preventing a nuclear accident," he tweeted. "I am continuing my efforts towards this goal with a sense of utmost urgency."
— Associated Press
Russian official mocks Zelenskyy's trip to Washington
Maria Zakharova, the Russian Ministry of Foreign Affairs spokesperson, has mocked Ukrainian President Volodymyr Zelenskyy's trip to Washington DC and Ukraine's relationship with the U.S.
Ukraine's High Representative to the UN, Sergiy Kyslytsya, tweeted a picture of the U.S. Flag in Ukraine's customary yellow and blue colors on Twitter Thursday.
Zakharova then took to her own Telegram account to mock the image, stating: "the Ukrainian permanent representative to the United Nations has posted Ukraine's new flag to Twitter. We've talked about this for many years, but no one believed us! Congratulations!"
Russia has repeatedly falsely accused the U.S. and wider western world of being to blame for the war in Ukraine, accusing the West of fighting a proxy war in Ukraine, and of seeking to control the country.
— Holly Ellyatt
Russia's top military officer says Ukraine front stable, most forces concentrated on Donetsk
Russia's Chief of General Staff Valery Gerasimov said on Thursday that the frontline in Ukraine was stable, and that Russia had concentrated its forces on "completing the liberation" of Ukraine's eastern Donetsk region.
In an end of year message delivered to foreign military attaches and published by the defence ministry, Russia's top military officer said: "The situation on the front line has stabilised, with the main efforts of the Russian troops concentrated on completing the liberation of the territory of the Donetsk People's Republic."
Russia has, since its retreat from Kyiv in April, framed its war aims as taking full control of the eastern Donbas region, of which Donetsk region makes up half, alongside neighbouring Luhansk region. Russian forces control almost all of Luhansk region, but only around 60% of Donetsk region.
Since August, they have been bogged down in a costly and extended fight for Bakhmut, a Donetsk region industrial town with a pre-war population of around 70,000.
Russian defense minister visits troops in Ukraine
Russia's Defense Minister Sergei Shoigu has visited Russian troops fighting in Ukraine, according to the country's Ministry of Defense.
Shoigu inspected Russian units of Russian forces and "the conditions of deployment of personnel and military equipment" in Ukraine, the ministry said on Telegram.
Shoigu spoke to unit commanders and met with troops, thanking them, the ministry said, "for their exemplary performance of the tasks within the special military operation" as Russia calls its invasion of Ukraine.
— Holly Ellyatt
Kremlin says Patriot missiles for Kyiv won't help settle Ukraine conflict
The Kremlin on Thursday said that U.S. supplies of Patriot missile systems to Ukraine, announced during Ukrainian President Volodymyr Zelenskyy's visit to Washington on Wednesday, would not contribute to settling the conflict between Moscow and Kyiv, and would not prevent Russia from achieving its goals.
In a call with reporters, Kremlin spokesman Dmitry Peskov said that there had been no signs of readiness for peace talks during Zelenskiy's visit, and that this was evidence that the United States was fighting a proxy war with Russia "to the last Ukrainian".
Kherson region shelled 60 times on Wednesday, official says
Russian forces shelled the southern region of Kherson 60 times on Wednesday, according to a Ukrainian official.
Yaroslav Yanushevych, head of the Kherson regional military administration, said on Telegram that one person had died and six others were injured in the attacks, according to a Google translation of his post.
He added that the region had been shelled 60 times, using artillery, mortars, multiple launch rocket systems and tanks. Residential neighborhoods had come under fire, Yanushevych added, as well as the shipyard, private and apartment buildings.
CNBC was unable to immediately verify the information in the post.
— Holly Ellyatt
'No change for the better': Kyiv's energy situation remains dire, and could get worse
The electricity supplier covering the Kyiv region has warned that there is "no change for the better" as the capital and surrounding area struggle with power outages — with some areas having no power since drone attacks on Monday damaged more energy infrastructure.
Sergey Kovalenko, the CEO of Yasno, a major private energy supplier covering the Kyiv region, said on Facebook Wednesday night that "the supply situation in Kyiv is the toughest in the country today. There are those areas that receive light about 5 hours a day. There are those with light 2-3 hours a day. And there are those without light at all from the last shelling," he said, according to a NBC translation.
"The city cannot draw power from the country's energy system due to damage to high-voltage equipment," he added.
Kovalenko added that the key problem facing the city right now was not power generation, but damaged power networks, particularly transformers and substations.
"Does it get any better than now? Maybe when the repair work is over," he said. "Can it get any worse? Yes, if we get shot at again," he said. More precisely, the situation would get worse if the remaining functioning equipment is damaged, he said.
— Holly Ellyatt
Belarus' military likely taking on 'significant' role in training of Russian reservists, UK says
Russia's ally Belarus is likely taking a discreet but significant role in training Russian reservists, according to Britain's Ministry of Defense.
Reflecting on Russian President Vladimir Putin's visit to Minsk earlier this week to meet his Belarusian counterpart, Alexander Lukashenko, the U.K. said discussions there included talk of a "single defence space."
"Although Russia and Belarus prominently publicise Russian units' deployments into Belarus, the armed forces of Belarus have likely recently taken on a significant, but more discreet role in training thousands of newly mobilised Russian reservists," the ministry said in an intelligence update on Twitter.
"The likely use of Belarusian instructors is an attempt to partially remediate the lack of Russian military trainers, many of whom are deployed in Ukraine or have become casualties," it added.
Although Russia and Belarus have an extensive background of military cooperation, the training of mobilized Russian personnel by Belarusians represents something of a role reversal, the U.K. said.
"Belarusian forces have traditionally been considered by Russia as inferior to Russian forces and their employment as trainers is an indication of overstretch within the Russian military system."
— Holly Ellyatt
Zelenskyy gives Congress a Ukrainian battle flag from contested city of Bakhmut
At the close of an historic address to Congress, Zelenskyy presented House Speaker Nancy Pelosi, D-Calif., and Vice President Kamala Harris with a unique gift: A flag from the city that has become the spiritual epicenter of Ukraine's resistance to the Russian invasion.
"When I was in Bakhmut yesterday, our heroes gave me the battle flag, the flag of those who defend Ukraine, Europe and the world at the cost of their lives," said Zelenskyy. "They asked me to bring this flag to you, to the U.S. Congress, to members of the House of Representatives and Senators whose decisions can save millions of people."
"So let these decisions be taken. Let this flag stay with you, ladies and gentlemen. This flag is a symbol of our victory in this war. We stand, we fight, and we will win because we are united, Ukraine, America and the entire free world," he said. Pelosi and Harris gave Zelenskyy an American flag that was flown over the U.S. Capitol earlier in the day.
The small city of Bakhmut in eastern Ukraine has seen some of the fiercest hand-to-hand fighting of the war in recent months, as both Ukraine and Russia have bestowed outsized significance on the city's value as a symbolic and strategic prize.
The Bakhmut flag presentation was one of several moments in Zelenskyy's speech during which he made a point of acknowledging the crucial role that Congress plays in approving U.S. foreign aid to countries like Ukraine.
The timing was no accident: Both chambers of Congress are set to vote in the coming days on a federal funding bill that contains $44.9 billion in military and economic aid for Ukraine.
— Christina Wilkie
'We'll celebrate Christmas' by candlelight in bomb shelters, Zelenskyy tells Congress
Four days before Christmas, Zelenskyy painted a vivid picture of how his country would celebrate the holiday, despite being under near constant Russian artillery attack and with millions of people without electricity or running water in freezing temperatures.
"We'll celebrate Christmas, and even if there is no electricity, the light of our faith in ourselves will not be put out," he said in a rousing speech to a joint meeting of Congress. "If Russian missiles attack us, we'll do our best to protect ourselves. If they attack us with Iranian drones and our people have to go to bomb shelters on Christmas Eve, Ukrainians will still sit down at the holiday table and cheer up each other," he said.
"We don't don't have to know everyone's wish, as we know that all of us millions of Ukrainians wish the same. Victory, only victory."
— Christina Wilkie
Zelenskyy evokes Battle of the Bulge, Saratoga in appeal to U.S. Congress
Zelenskyy received loud applause from the U.S. Congress Wednesday night as he compared Ukraine's fight for its survival to U.S. battles from World War II and the American Revolution.
Zelenskyy compared Ukraine's ongoing defensive stand against Russian troops in the east of the country around Bakhmut to American troops' successful defense against German troops in the Battle of the Bulge in 1944. Both battles raged through the Christmas season.
Zelenskyy went on to say he hopes for a turning point in the Ukraine war in 2023, similar to American revolutionaries' victory at Saratoga. At that series of battles in 1777, Americans defeated imperial British troops in Upstate New York.
France began openly supplying the Americans with arms after Saratoga. Continued weapons shipments were part of Zelenskyy's plea before Congress.
"We Ukrainians will also undergo our war of independence with dignity and success," the Ukrainian president said.
— Ted Kemp
'Your money is not charity,' Zelenskyy assures Congress of $45 billion Ukraine aid package
Zelenskyy was frank about the need for more aid from the U.S. Congress and the United States in order for Ukraine to drive Russian forces from his country.
"We have artillery. Yes. We have it. Is it enough? Honestly, not really," he said in a memorable speech to a joint meeting of Congress.
"I believe there should be no taboos between us in our alliance. Ukraine never asked the American soldiers to fight on our land instead of us," he said. "And I assure you that Ukrainian soldiers can perfectly operate American tanks and planes themselves."
"Financial assistance is also critically important, and I would like to thank you, thank you very much," Zelenskyy continued. "Thank you for both financial packages you have already provided us with and the ones you may be willing to decide on."
"Your money is not charity. It is an investment in global security and democracy, that we handle in the most responsible way."
Zelenskyy's assurance about Ukrainian stewardship of U.S. funds came as Congress prepares to authorize a $44.9 billion military and humanitarian aid package for Ukraine over the coming year.
One of the goals of Zelenskyy's last-minute trip to Washington was to firm up support for this aid.
— Christina Wilkie
Congress gives Zelenskyy big, long standing ovation
Ukrainian President Volodymyr Zelenskyy received a long standing ovation from members of Congress and Cabinet secretaries in the House chamber tonight as he arrived to give an historic speech to a joint session of the legislature.
Both Republicans and Democrats stood and clapped and cheered for at least two minutes.
""It's too much for me," Zelenskyy said at the podium, placing his hand to his heart. "All this for our great people. Thank you."
— Christina Wilkie
Russia's attacks on civilian targets led to Zelenskyy White House meeting, Kirby says
Russia's increased attacks on civilian infrastructure and "civilian targets" in Ukraine necessitated the meeting between Biden and Zelenskyy, White House National Security Council spokesman John Kirby said on MSNBC's "Morning Joe."
"As winter approaches, these kinds of attacks against infrastructure are really changing the face and the character of the war," Kirby said. "The president felt it was important to have this face to face meeting with President Zelenskyy to discuss the way forward."
Kirby said Biden would detail plans for air defense assistance when the president speaks Wednesday and make it clear the Ukraine has the full backing of the United States.
The recent civilian targets, Kirby said, are another example of how Russian President Vladimir Putin shows "no interest at all in trying to find a path out of this war."
— Emma Kinery