This has been CNBC's live blog covering updates on the war in Ukraine. [Follow the latest updates here.]

Ukraine's President Volodymyr Zelenskyy said on Sunday that he had visited two towns near the front in the Donbas region in eastern Ukraine, where Russian forces are concentrated. He also visited Zaporizhzhia, which is partly under Russian control.

The U.K., meanwhile, said it is sending Ukraine multiple-launch rocket systems that can strike targets up to 50 miles away. The move has been coordinated with the U.S., which announced a similar military aid package last week.

It comes after Russian President Vladimir Putin issued a broad warning to the West on Sunday that his military will strike new targets if the West starts supplying Ukraine with longer-range missiles.

Blinken says Russia is 'exporting starvation and suffering' beyond Ukraine

Russia's blockade of key Ukrainian ports, which has stalled critical grain exports, has hurt people around the world, U.S. Secretary of State Antony Blinken said.

"The Kremlin needs to realize that it is exporting starvation and suffering well beyond Ukraine's borders," he said during a roundtable on food insecurity with business leaders and Agriculture Secretary Tom Vilsack.

Blinken noted that African countries are "experiencing an outsized share of the pain."

Ukrainian President Volodymyr Zelenskyy has sought a corridor to export grains held up in Ukrainian ports. United Nations Secretary-General Antonio Guterres has held talks to try to free up the grain supply.

— Jacob Pramuk

Photos: Ukrainians operate US-donated M777 howitzer near front line in Donetsk

— Reuters

Russia sanctions U.S. Treasury and Energy secretaries, defense and media executives

Russia has imposed personal sanctions on 61 U.S. officials including Treasury Secretary Janet Yellen and Energy Secretary Jennifer Granholm and leading defense and media executives, the Russian foreign ministry said.

The ministry said it had imposed personal sanctions, which ban those named from entering Russia, in retaliation for "constantly expanding U.S. sanctions against Russian political and public figures, as well as representatives of domestic business."

It said the individuals were the heads of leading military-industrial corporations, media platforms, rating agencies and aircraft and shipbuilding companies, as well as individual U.S. State Department officials "involved in fake reports about 'malicious' Russian cyber attacks."

— Reuters

Zelenskyy seeks corridor for grain vessels

Ukraine's president is asking for a secure corridor for Ukrainian vessels to be able to ship out grain and prevent food shortages in Africa and Asia.

Volodymyr Zelenskyy told a news conference that Kyiv is in talks with countries like Turkey and the U.K. about security guaranties for Ukrainian ships.

"It is important for us that there is a security corridor ... that the fleet of this or that country ensures the shipping of the grain," Zelenskyy said.

Zelenskyy adds that "if now we have 22-25 million tons blocked there, in the fall we might have 75 (million tons)."

"What are we going to do? he asked. "That's why we can't do without the ports."

— Associated Press

DOJ moves to seize 2 planes from Russian oligarch Roman Abramovich

A federal judge ordered the Department of Justice to seize two private planes owned by Roman Abramovich, the Russian oligarch and ally of Vladimir Putin, documents show.

The U.S. in a charging letter accused Abramovich of violating U.S. export rules by re-exporting a Gulfstream G650ER and a Boeing 787-8 Dreamliner to Russia. The Biden administration tightened those regulations following Russia's invasion of Ukraine, in order to limit the Kremlin's access to equipment that could aid its military campaign.

The customized Boeing is believed to be worth about $350 million, making it one of the most expensive private jets in the world, according to the letter from the Department of Commerce. The Gulfstream was sold in 2020 for $60 million, the Commerce Department said.

In a sworn affidavit, FBI special agent Alan Fowler said that Abramovich owned both planes through a series of shell companies. Since March, the Boeing has been in Dubai and the Gulfstream has been in Russia, Fowler wrote.

"I am satisfied that there is probable cause to believe that the property so described is subject to seizure and civil forfeiture," U.S. Magistrate Judge Sarah Cave said in an order authorizing the warrant.

— Kevin Breuninger

U.S. does not want a war with Russia, Joint Chiefs Chairman Milley says

Chairman of the Joint Chiefs of Staff Mark Milley reiterated that the United States does not seek a direct conflict with Russia.

"The United States doesn't want a war with Russia. NATO doesn't want a war with Russia," he told NBC News in Normandy, France, during events marking the 78th anniversary of the D-Day invasion.

He said the U.S. would continue to provide Ukraine with military equipment as the country fights off a Russian invasion that has now gone on more than 100 days.

Milley noted that Russia has faced "a lot of challenges" in its attempts to gain ground in Ukraine, "due to the bravery and sacrifice of the Ukrainian people."

— Jacob Pramuk

Little cheer for Russian beer lovers as sanctions bite

"Sorry, that was the last bottle of Czech beer we had," said a waiter at a central Moscow restaurant, a month after Russia sent troops into Ukraine and the West imposed sweeping sanctions.

More than 100 days into what Russia calls a special military operation in Ukraine, foreign alcohol is still available in Moscow pubs, but the once ample reserves are dwindling.

"Some pubs accumulated large stocks when it all started. But, as far as I know, there have been no new deliveries ordered and confirmed after Feb. 24," said Alexander Skripkin, who manages two bars in Moscow.

Many foreign companies including leading Western brewer in the country Carlsberg, Anheuser-Busch InBev and Heineken, have suspended sales in Russia and shipping trade has plummeted.

— Reuters

Another Russian general reportedly killed in Ukraine

One of Moscow's top military generals has reportedly been killed in Ukraine, marking another high-profile loss for Russia if confirmed.

Ukraine's Centre for Strategic Communications (StratCom) of the Office of the Commander-in-Chief of the Ukrainian Armed Forces reported the death of Russian Major General Roman Kutuzov in a battle near Popasna in the Luhansk region.

Alexander Sladkov, a war correspondent with Russian state news channel Rossiya-1, also reported on the death, stating on his Telegram channel that Kutuzov was the fourth general to die in battle and had died after leading his soldiers into an attack.

The death has not yet been confirmed by Russia's military, however, and CNBC was unable to verify the claims.

Russia has confirmed that three of its generals have died. Kyiv has claimed that 12 of Russia's generals have died during the conflict.

— Holly Ellyatt

Russian foreign minister cancels visit to Serbia after plane blocked

A trip by Russia's foreign minister to Serbia has been canceled after several European countries would not allow the plane to travel to the southeastern European country.

Bulgaria, North Macedonia and Montenegro closed their airspace so that Russian Foreign Minister Sergei Lavrov's official plane could not travel to Serbia's capital Belgrade.

Lavrov described the move to block his plane as "unprecedented" and "outrageous" and said he had not received an explanation for the decision, according to comments reported by Russian state news agency TASS.

He said that he would instead invite his Serbian counterpart to visit him in Moscow, commenting that "the main thing is no one will be able to destroy our relations with Serbia," a country with which Russia has strong ties.

— Holly Ellyatt

Situation in Severodonetsk has 'deteriorated,' official says, likening its destruction to Mariupol's

The situation in Severodonetsk, the focus of intense fighting in eastern Ukraine between Russian forces and Ukrainian troops, has "deteriorated somewhat," according to the governor of the Luhansk region.

"The fighting is very dynamic," Serhiy Haidai, governor of the eastern Luhansk province, said in an update on Telegram on Monday.

"Half of the city was recaptured during the counteroffensive, but we are now holding positions in the industrial zone," he said, adding that the amount of shelling in the Severodonetsk and Lysychansk cities has "increased tenfold."

He said that there are a number of cities in the Luhansk region that are in a situation comparable to Mariupol, the heavily destroyed southern port city now in the hands of Russia.

"Now the Russians are leveling Sievierodonetsk and Lysychansk to the ground," he said.

CNBC was unable to immediately verify the information.

— Holly Ellyatt

Heavy fighting is continuing around Severodonetsk in eastern Ukraine, UK says

Heavy fighting is continuing around the contested town of Severodonetsk in eastern Ukraine, Britain's Ministry of Defense said in its daily intelligence update.

In addition, Russian forces continue to push toward Sloviansk as part of their attempted encirclement of Ukrainian forces, the ministry said.

Russian forces are also likely to have moved multiple air defense assets to Snake Island in the western Black Sea in order to provide protection for its ships operating in the area, according to the ministry. That follows the loss of the flagship Moskva cruiser in April.

"Russia's activity on Snake Island contributes to its blockade of the Ukrainian coast and hinders the resumption of maritime trade, including exports of Ukrainian grain," the U.K. said.

— Holly Ellyatt

Zelenskyy visits front lines despite heavy fighting

Ukraine President Volodymyr Zelenskyy visited front line areas where his country's troops are fighting against invading Russian forces, Sky News reported Monday.

Zelenskyy went to Lysychansk and Soledar in Ukraine's east, where Russia is using indiscriminate rocket and artillery attacks against wide areas. The cities are in Luhansk and Donetsk, respectively.

The Ukrainian president earlier visited Zaporizhzhia, Sky said. That city is on the Dnipro River, near the southern front facing Russian troops.

Video circulating on Twitter claimed to show Zelenskyy visiting positions near Lysychansk, where he handed out commendations to Ukrainian soldiers.

CNBC was unable to confirm the veracity of that video.

— Ted Kemp

The UK will supply Ukraine with multiple-launch rocket systems

Britain is sending Ukraine multiple-launch rocket systems that can strike targets up to 50 miles away — in a coordinated response with the U.S. to Russia's invasion, Reuters reported.

"These highly capable multiple-launch rocket systems will enable our Ukrainian friends to better protect themselves against the brutal use of long-range artillery, which (Russian President Vladimir) Putin's forces have used indiscriminately to flatten cities," Defense Secretary Ben Wallace said in a statement, according to Reuters.

The U.S. also said last week it is supplying Ukraine with High Mobility Artillery Rocket Systems. Rockets from the HIMARS can travel more than 43 miles, according to the U.S. army.

The U.K. said Ukrainian forces will be trained on how to use the new systems in Britain, according to Reuters.

— Chelsea Ong

About 800 people are hiding in bomb shelters under chemical plant in Severodonetsk, regional governor says

Roughly 800 people are hiding across several bomb shelters located underneath the Azot chemical factory in Severodonetsk, the head of the Luhansk region military administration told CNN.

"There are locals there, who were asked to leave the city," Serhiy Haidai told the news outlet. "But they refused. There are also children there, but not many of them."

NBC News could not immediately verify the claims.

Regional Ukrainian officials later said that Russian forces fired on the Azot factory and hit an administrative building and a warehouse where methanol was stored, CNN reported.

Severodonetsk is now split between Russian and Ukrainian control, Haidai said, according to an NBC News translation.

— Jessica Bursztynsky

Several explosions hit Ukrainian capital Kyiv, mayor says

Several explosions were heard in Ukraine's capital Kyiv after missile strikes on infrastructure, the city's mayor said, according to an NBC News translation.

Mayor Vitaliy Klychko said one person was sent to the hospital and that services were already working on the affected sites.

The mayor of another city in the region, Brovary, also urged residents to remain calm and in safe places after reports of enemy fire in the area.

CNBC was not able to confirm the report. Military developments on the ground remain difficult to confirm in a rapidly shifting situation.

— Christine Wang

Putin warns West against sending longer-range missiles, will strike harder

Russian President Vladimir Putin issued a broad warning to the West that his military will strike new targets if the U.S. starts supplying Ukraine with longer-range missiles, the TASS news agency reported.

Putin said in an interview aired on the Russia-1 TV channel that if those weapons are supplied: "We will draw the relevant conclusions and take our own means of attack, which, for the purpose of hitting the objects which we have not been hitting so far, we have enough of."

Putin did not elaborate on what targets he would attempt to strike.

Ukrainian officials have been asking the West for weeks to send advanced, longer-range rocket systems to aid them in the war. Officials in Washington have had to weigh the benefits of sending the weapons with the risk of provoking Putin into committing further atrocities.

President Joe Biden said in a New York Times op-ed last Thursday the U.S. would provide Ukraine with more advanced rocket systems and munitions.

— Jessica Bursztynsky

Read CNBC's previous live coverage here:

UK to supply Ukraine with rocket systems; Kyiv airstrikes hit train-repair facility