Ukraine is ready for peace talks but will not withdraw its troops from additional territory first as Moscow has demanded, President Volodymyr Zelenskiy said.

In comments to reporters released on Tuesday, he said he was happy for talks to be held anywhere, except in Russia itself or on the territory of its close ally Belarus.

Plans for a summit in Budapest this month between US President Donald Trump and Russia's Vladimir Putin were put on hold after Moscow stuck to demands, including that Ukraine cede more territory as a condition for a ceasefire. Trump has backed Ukraine's call for an immediate ceasefire on current lines.

"It's absolutely clear that we're approaching diplomacy only from the position where we currently stand. We will not take any steps back and leave one part of our state or another," Zelenskiy said.

"And the important result is that the American side finally made this a public signal: President Trump came out with such a message."

Zelenskiy said he was happy to attend talks, including in Hungary, despite reservations about some of the positions of its Prime Minister Viktor Orban, who, he said, "blocks everything for Ukraine".

"If there will be results, then God bless - let the talks take place anywhere," he said. "It almost doesn't matter, just not in Russia, of course, and definitely not in Belarus."

Zelenskiy also urged US lawmakers to pass tougher restrictions on Russia after Trump imposed sanctions on Moscow's two biggest oil companies.

Ukraine would need stable financing from its European allies for another two or three years, Zelenskiy said.