Biden calls for war crimes trial against Putin: 'You saw what happened in Bucha'

• Biden called for a war crimes trial against Putin following civilian massacres in Ukraine.
• "You may remember I got criticized for calling Putin a war criminal," Biden told reporters on Monday.

President Joe Biden on Monday called for a war crimes trial against Russian President Vladimir Putin following revelations of civilian massacres in Bucha, a suburb of the Ukrainian capital of Kyiv.

"You may remember I got criticized for calling Putin a war criminal," Biden told reporters as he arrived back at the White House from Delaware, where he spent the weekend. "Well the truth of the matter is, you saw what happened in Bucha. This warrants him — he is a war criminal. But we have to gather the information."

He then called for the continued supply of lethal military aid to the country.

"We have to continue to provide Ukraine with the weapons they need to continue the fight," he said. "And we have to gather all the details, so this could be an actual — have a war crime trial."

"This guy is brutal, and what's happening in Bucha is outrageous, and everyone's seen it," he added. Asked by a reporter whether he believed it constituted a genocide, Biden stopped short.

"No, I think it is a war crime," he said. He also said he's "seeking more sanctions" against Russia.

"He should be held accountable," said Biden of Putin.

While Biden has previously called Putin a "war criminal," this is the first time he's suggested that the Russian leader should face a formal trial.

He also recently drew criticism for declaring that Putin "cannot remain in power," which he said was an expression of his own moral outrage against Russia's actions in Ukraine. "I make no apologies for it," said Biden last week.

Independent journalists and Ukrainian officials shared horrifying images from Bucha, including the bodies of civilians lying dead in the streets. Some of those killed had their hands tied behind their backs, and had apparently been executed. Roughly 300 civilians were killed, according to Bucha's mayor.

Ukrainian President Volodymyr Zelenskyy, who visited Bucha on Monday, explicitly accused Russia of genocide over the apparent atrocities in Bucha.

"Indeed, this is genocide," Zelenskyy said on Sunday during an interview on "Face the Nation" on CBS News. "The elimination of the whole nation and the people. We are the citizens of Ukraine we have over 100 nationalities. This is about the destruction and extermination of all these nationalities."

Meanwhile, the Russian government has pushed conspiracy theories about Bucha, claiming that the images were faked or staged while denying that it was involved in the massacre.

Though Russia has been widely accused of war crimes in the Ukraine war, actually prosecuting war crimes is a far more complicated matter. Experts have said it would take years to build a case against Russian President Vladimir Putin and he would be unlikely to ever face justice for war crimes. Neither Russia nor Ukraine are members of the International Criminal Court (ICC), but Ukraine has "accepted the court's jurisdiction over alleged crimes committed on its territory since November 2013, and in so doing, the obligation to cooperate with the court," per Human Rights Watch.