Warsaw, Mar 26 (IANS): US President Joe Biden again called his Russian counterpart a "war criminal" due to the Moscow's continued invasion of Kiev.

Biden made the remarks during a joint briefing on the humanitarian efforts for Ukraine with Polish President Andrej Duda on Friday in Rzeszow, located close to the Poland-Ukraine border.

In his opening remarks, Biden, who arrived in Poland on Friday, said the "single-most important thing that we can do from the outset is keep the democracies united in our opposition and our effort to curtail the devastation that is occurring at the hands of a man who, quite frankly, I think is a war criminal".

"And I think it will meet the legal definition of that as well," he said.

On March 16, Biden had called Putin a "war criminal" for the first time which evoked condemnation from Russia.

On Wednesday, the State Department made a formal assessment that Russian forces have committed war crimes in Ukraine.

"Based on information currently available, the US government assesses that members of Russia's forces have committed war crimes in Ukraine. Our assessment is based on a careful review of available information from public and intelligence sources," Secretary of State Blinken had said in a statement.