• Ukrainian President Volodymyr Zelenskyy called for a Nuremberg-style tribunal to investigate and prosecute Russian war crimes.
• Zelenskyy's appearance before the United Nations Security Council follows Ukrainian claims that at least 300 civilians were tortured and killed in Bucha by Russian troops.
• U.S. Ambassador Linda Thomas-Greenfield introduced a proposal to suspend Russia from the Human Rights Council.

WASHINGTON — Ukrainian President Volodymyr Zelenskyy called for a Nuremberg-style tribunal to investigate and prosecute Russian war crimes in a speech before the United Nations Security Council.

"The Russian military and those who gave them orders must be brought to justice immediately for war crimes in Ukraine," Zelenskyy said in his nearly 20-minute speech on Tuesday.

Zelenskyy's appearance before the U.N. Security Council follows Ukrainian claims that at least 300 civilians were tortured and killed in Bucha by Russian troops. The bodies were discovered after Moscow withdrew its troops from the suburb near Ukraine's capital. Zelenskyy described the aftermath in Bucha, which he saw firsthand on Monday, as a "genocide" and accused Russia of war crimes.

"The massacre in our city of Bucha is only one, unfortunately, only one of many examples of what the occupiers have been doing on our land for the past 41 days," Zelenskyy said, adding "the world has yet to see" what Russia has done elsewhere in Ukraine.

Over the weekend, the Russian invasion sparked renewed global outrage as horrific images emerged of bodies scattered across the streets, some with their hands tied and gunshot wounds to the back of the head.

"Anyone who has given criminal orders and carried out them by killing our people will be brought before the tribunal which should be similar to the Nuremberg tribunals," Zelenskyy said.

The Ukrainian leader's remarks came before a U.S.-led proposal to suspend Russia from the Human Rights Council.

U.S. Ambassador Linda Thomas-Greenfield introduced the proposal to the Security Council, where Russia holds a permanent membership and wields the right to veto resolutions.

"Based on the currently available information, the United States has assessed that members of Russia's forces have committed war crimes in Ukraine," Thomas-Greenfield said on Tuesday. "Given the growing mountain of evidence, Russia should not have a position of authority in a body whose purpose, whose very purpose is to promote respect for human rights. Not only is this the height of hypocrisy, it is dangerous," she said.

She said Russia's membership on the council hurts its credibility, "undermines the entire U.N. and it is just plain wrong."

On Monday, President Joe Biden called Russian leader Vladimir Putin a "war criminal" who should be put on trial for ordering violence in Ukraine.

"This guy is brutal, and what's happening in Bucha is outrageous and everyone's seen it," Biden told reporters gathered at Fort McNair, in Washington, D.C., adding, "I think it is a war crime ... He should be held accountable."

Before departing for Brussels to attend meetings at NATO and the G-7, Secretary of State Antony Blinken told reporters traveling with him that the reports of Russian war crimes in Ukraine are "more than credible."

"What we've seen in Bucha is not the random act of a rogue unit. It's a deliberate campaign to kill, to torture, to rape, to commit atrocities. The reports are more than credible. The evidence is there for the world to see," Blinken said.

Earlier on Tuesday, NATO Secretary-General Jens Stoltenberg said the alliance is working with the U.N.'s International Criminal Court on investigating Russian war crimes in Ukraine.

"Targeting and murdering civilians is a war crime. All the facts must be established and all those responsible for these atrocities must be brought to justice," the alliance chief said.

Stoltenberg, who briefed reporters from NATO's headquarters before Wednesday's foreign minister's meeting, said the alliance had reliable evidence of war crimes committed in Bucha as well as in other cities in Ukraine.