Joe Biden has called for Vladimir Putin to face a war crimes trial, as he promised additional sanctions on Moscow.

Appalled by the situation in the Ukrainian town of Bucha, where hundreds of civilians have been found dead, the US president said: “What’s happened in Bucha is outrageous and everyone has seen it. I think it is a war crime.

“We have to gather all the details so that we can have a war crimes trial. He should be held accountable.”

There have been allegations that Russian soldiers have raped, mutilated, tortured and executed men, women and children in the key commuter town outside Kyiv.

Asked if he thinks the actions constitute “genocide”, Mr Biden said: “No, I think it is a war crime.”

“I’m seeking more sanctions,” Mr Biden said. “He should be held accountable.”

Investigations into the Russian president’s actions had started before the new allegations of atrocities outside Kyiv.