STORY: The angry comments by Zelenskiy come as Ukrainian troops are facing a renewed offensive in two eastern regions that Russian-speaking separatists seized part of in 2014.

The New York Times editorial board said on May 19 that a negotiated peace might require Kyiv to make some hard decisions, given that a decisive military victory was not realistic, and former U.S. Secretary of State Henry Kissinger this week suggested at the World Economic Forum in Davos that Ukraine should let Russia keep Crimea, which it annexed in 2014.

"Whatever the Russian state does, you will always find someone who says 'Let's take its interests into account'," Zelenskiy said in a late night video address.

"You get the impression that Mr Kissinger doesn't have 2022 on his calendar, but 1938, and that he thinks he is talking to an audience not in Davos but in then Munich."

In 1938, Britain, France, Italy and Germany sighed a pact in Munich that gave Nazi dictator Adolf Hitler land in the then Czechoslovakia as part of a failed attempt to persuade him to abandon further territorial expansion.

With its invasion now into its fourth month, Russia still has only limited gains to show for its worst military losses in decades, while much of Ukraine has suffered devastation as Moscow steps up strikes to offset its slow progress.