Russian President Vladimir Putin has invited Ukraine to take part in "direct talks" on 15 May, hours after European leaders urged Moscow to agree to a 30-day ceasefire.
In a rare televised late-night address from the Kremlin, Putin said Russia was seeking "serious negotiations" aimed at "moving towards a lasting, strong peace".
Earlier on Saturday, UK Prime Minister Sir Keir Starmer travelled to Kyiv with counterparts from France, Germany and Poland to put pressure on Russia to commit to an unconditional ceasefire, starting Monday.
Kremlin spokesman Dmitry Peskov later said Moscow would "have to think this through" - but warned that "trying to pressure us is quite useless".
In his own statement, Putin said he could "not rule out" the possibility that the talks could result in Russia and Ukraine agreeing "a new truce". But he did not address calls for a 30-day ceasefire directly.
The Russian leader said the proposed talks should be held in the Turkish city of Istanbul, as they have been before, and that he would speak to Turkey's President Recep Tayyip Erdogan on Sunday to discuss the details.
Kyiv has not responded to the invitation.
The Ukrainian capital played host on Saturday to Sir Keir, France's Emmanuel Macron, Germany's Friedrich Merz and Poland's Donald Tusk, who form part of the "coalition of the willing" - a group of countries committed to supporting Ukraine.
Alongside Ukrainian President Volodymyr Zelensky, they took part in a joint news conference.
The leaders warned that "new and massive" sanctions would be imposed on Russia's energy and banking sectors should Putin not agree to the unconditional 30-day ceasefire "in the air, at sea and on land".
They also said they had discussed the proposal with Donald Trump. Sir Keir later told the BBC the US president was "absolutely clear" that their suggestion of an immediate ceasefire was a "demand that must be met".
After the meeting, Zelensky thanked the assembled leaders for "standing with" Ukraine.
"Today we will focus on how to build and guarantee real and lasting security," he said.
Responding to the proposal, the Kremlin's Peskov said: "It is a new development. But trying to pressure us is quite useless."
Russian state media also quoted him as saying that statements from Europe were "generally confrontational in nature rather than aimed at trying to revive our relations".
Moscow has previously said that before considering a ceasefire, the West must first halt its military aid to Ukraine.
BBC