Russian President Vladimir Putin has proposed direct talks with Ukraine on May 15 in Istanbul, which he said should be aimed at achieving a durable peace and eliminating the root causes of the war.
Putin sent thousands of troops into Ukraine in February 2022, triggering the gravest confrontation between Russia and the West since the 1962 Cuban Missile Crisis.
He said that Russia was proposing direct talks with Ukraine in Istanbul in an attempt to "eliminate the root causes of the conflict" and "to achieve the restoration of a long-term, lasting peace".
"It was not Russia that broke off negotiations in 2022. It was Kyiv. Nevertheless, we are proposing that Kyiv resume direct negotiations without any preconditions," Putin said on Sunday, referring to failed talks shortly after the Russian invasion of 2022.
"We offer the Kyiv authorities to resume negotiations already on Thursday, in Istanbul," Putin said.
"Our proposal, as they say, is on the table, the decision is now up to the Ukrainian authorities and their curators, who are guided, it seems, by their personal political ambitions, and not by the interests of their peoples."
Earlier, major European powers threw their weight behind an unconditional 30-day Ukraine ceasefire, with the backing of US President Donald Trump, and threatened Putin with "massive" new sanctions if he did not accept within days.
The leaders of the United Kingdom, France, Germany, Poland and Ukraine set the start of the ceasefire for May 12 at a meeting in Kyiv, during which they held a phone call with Trump.
"So all of us here together with the US are calling Putin out. If he is serious about peace, then he has a chance to show it," UK Prime Minister Keir Starmer told a press conference.
"No more ifs and buts, no more conditions and delays."
Kremlin spokesman Dmitry Peskov said on Saturday after the European leaders' announcement that Russia would consider a proposal for a 30-day ceasefire in Ukraine while Russia had its own position, the TASS news agency reported.
Sanctions against Russia have been toughened repeatedly since its full-scale invasion in 2022, without ending the war.
Trump, who did not immediately comment publicly on the European leaders' remarks, has also signalled frustration with what the US views as Putin's foot-dragging over a ceasefire.
"In the event that the ceasefire is violated, massive sanctions will be prepared, in co-ordination between the Europeans and the United States," French President Emmanuel Macron said.
Ukrainian President Volodymyr Zelenskiy said he and the visiting leaders had agreed the unconditional ceasefire must start on Monday and cover air, sea and land.
If Russia refused, it would face new sanctions, including the strengthening of punitive measures targeting its energy and banking sectors, he said.
Macron said that if the ceasefire went ahead, it would be monitored mainly by the US while European countries would contribute.
The European leaders said the terms of a peace deal would be negotiated during the 30-day pause in fighting.
"We have no illusions that the ceasefire will be breached," Zelenskiy said.
On the eve of the summit, the US embassy in Kyiv warned of a "potentially significant" air attack in the coming days.
When the European leaders arrived in Kyiv by train on Saturday, a screen on the platform announced the arrival of the "Bravery Express".
Zelenskiy accompanied them as they paid their respects at a Kyiv memorial honouring Ukrainian soldiers killed in the war.
The visit falls on the final day of a May 8-10 ceasefire declared by Putin that Ukraine did not accept, denouncing it as a sham.
Both sides have accused each other of violating it.