"We all want this war to end in a fair way -- with no rewards for Putin, especially no land," Zelensky said via videoconference at a summit organised by Poland.

The comment comes amid reports the United States suggested to freeze the front lines and accept the Russian control of the Crimean peninsula that it seized in 2014, something Zelensky has refused.

But US President Donald Trump said Sunday that he believed Zelensky might concede the Black Sea peninsula as part of a settlement.

Russia has also repeatedly demanded to keep the territory in southern and eastern Ukraine that it occupies and for Kyiv to cede even more land.

Moscow holds about 20 percent of Ukraine's territory after launching its grinding assault that has killed thousands of people.

Washington has said that this week will be "critical" for peace efforts.

- Unconditional ceasefire -

Zelensky later on Tuesday once again called for a full and unconditional ceasefire, which must be the first step before any negotiations.

"They must take clear steps to end the war, and we insist that an unconditional and complete ceasefire must be the first step," he said in an evening address.

Putin on Monday ordered a surprise three-day ceasefire on May 8-10, which coincides with Moscow's World War II commemorations, drawing ire from Kyiv, which demanded Moscow pause hostilities immediately.

"Right now, they are worried that their parade is in jeopardy, and rightly so," Zelensky said in his evening address, "but they should be worried that this war is still going on," he added.

This year, Russia will mark on May 9 the 80th anniversary of its Victory Day for what is known in Russia as the Great Patriotic War with massive parades in Moscow and cities across the country.