Vladimir Putin has until midnight to agree to a 30-day ceasefire with Ukraine or leading European states, including the UK, will impose new sanctions against Russia, the German government's spokesman has said. "The clock is ticking– there are still 12 hours until the end of the day", Stefan Kornelius said at noon at Central European Summer Time (CEST).

"When today is over, preparations for sanctions measures will be initiated at the level of political advisors. At the same time, we are preparing the 17th package of sanctions in Brussels. These preparations are taking place in parallel with the negotiations [in Istanbul]," he said in Berlin.

Sir Keir Starmer's "coalition of the willing" met in Kyiv on May 10 and demanded that the Kremlin agree to a 30-day ceasefire by the end of May 12.

Following the agreement, Mr Zelensky said: "The most important thing is that we've agreed that a complete and unconditional ceasefire for at least 30 days should begin on Monday, May 12. Together, we demand this from Russia and know that the United States supports us in this regard."

The Ukrainian war leader added: "The ceasefire must be comprehensive; in the air, at sea and on land. It's entirely possible to ensure the monitoring of the ceasefire in coordination with the United States. That's totally realistic."

Putin meanwhile said he is ready for "direct talks" with Kyiv on May 15 in Istanbul, Turkey. However, he made no mention of the 30-day ceasefire proposal.

"We propose resuming direct negotiations with the Kyiv regime on Thursday, May 15, in Istanbul, where they were previously suspended", he said, according to Russian state media outlet TASS.

The Kremlin spokesman Dmitry Peskov told CNN on Saturday that Russia would consider the European peace proposal. "We have to think about it, these are new developments. We have our own position", he said.