Ukrainian President Volodymyr Zelensky said on Sunday he expects Moscow to commit to a 30-day ceasefire, adding that Kyiv was ready to meet Russia for direct truce talks.

Earlier, Russian President Vladimir Putin called on Kyiv to meet in Istanbul for talks on May 12 at a nighttime press conference in the Kremlin, but did not commit to a ceasefire.

On a visit to Kyiv on Saturday the leaders of France, the UK, Germany and Poland pressured Russia – with US President Donald Trump's support – to commit to an unconditional ceasefire in Ukraine starting from Monday.

"There is no point in continuing the killing even for a single day. We expect Russia to confirm a ceasefire – full, lasting and reliable – starting tomorrow, May 12, and Ukraine is ready to meet," Zelensky said on social media.

Sounding a rare note of optimism, the Ukrainian leader likewise said he saw positive signals from Russia.

"It is a positive sign that the Russians have finally begun to consider ending the war," Zelensky said.

"The entire world has been waiting for this for a very long time. And the very first step in truly ending any war is a ceasefire."

Kyiv and its Western allies have argued that an unconditional ceasefire would be the only way to help find a diplomatic solution to the three-year conflict, Europe's worst since World War II.

Russia and Ukraine have not held direct talks since the war began in February 2022. (AFP)