The leaders of Germany, France, the United Kingdom and Poland have told Russian leader Vladimir Putin to agree to a 30-day ceasefire starting on Monday or face possible “massive” sanctions, according to French President Emmanuel Macron, on a highly symbolic visit to Kyiv.

The demand comes with the backing of the White House after a joint phone call with President Donald Trump, the Europeans said.

Standing alongside Ukraine’s President Volodymyr Zelensky in Kyiv, the four leaders – Macron, new German Chancellor Friedrich Merz, Britain’s Prime Minister Keir Starmer and his Polish counterpart Donald Tusk – said the ceasefire should be observed on land, at sea and in the air.

If successful, Macron said, it could pave the way for “the immediate launch of negotiations to build a robust and lasting peace.”

In an exclusive interview with CNN’s Frederik Pleitgen shortly after the leaders called for the ceasefire, Kremlin spokesperson Dmitry Peskov said that Russia is “resistant to any kind of pressure.”

“Europe is actually confronting us very openly,” Peskov said, adding that Russian President Vladimir Putin supports the idea of a ceasefire “in general,” but “there are lots of questions” about the recent proposal that still need answering. He did not expand on what these questions are.

The dramatic announcement gives Putin less than 36 hours to respond, and also means a complex mechanism of satellite monitoring and communications would need to become operational in the same, short time period.

“We have agreed that from Monday 12th of May, a full and unconditional ceasefire must start for at least 30 days,” Zelensky said.

“We demand it together from Russia and we know that the United States supports us in this.

“The unconditional ceasefire means no conditions and an attempt to put conditions on it is to signal an intention to drag out the war and undermine diplomacy.”

The four European leaders arrived together by train early Saturday morning and were met at Kyiv’s main railway station by Zelensky’s chief of staff, Andriy Yermak.

Their first public engagement was at Independence Square, where they stood to honour Ukraine’s fallen soldiers. Then it was on to the city’s Mariinsky Palace, where they met together for more than three hours.

Afterwards, the leaders sat together round a phone and spoke to Trump.

Ukraine’s Foreign Minister Andrii Sybiha posted a photo of the moment on social media, saying the call had been “fruitful.” There was no immediate response from the White House.

For two months now, Ukraine has said it wants an immediate 30-day ceasefire – a position promoted by Kyiv’s key European allies, and also by Trump.

Russia has so far refused to commit, saying it supports the idea of a 30-day ceasefire in principle but insists there are what it calls “nuances” that need addressing first.

Putin has often spoken about the need to address what he calls “root causes” – which are taken to mean, among others, the eastward expansion of NATO.

In a Truth Social post on Thursday, Trump wrote that “if the ceasefire is not respected, the US and its partners will impose further sanctions,” adding to a sense he is growing frustrated with Russian stalling.

Peskov told CNN on Saturday that Russia is “very grateful” for the US’ mediation efforts, but added that “at the same time, it’s quite useless to try to press on us.”

The inauguration of Trump in January ushered in a complete change in the US diplomatic focus on the war, with Ukraine and key allies fearful of a significant tilt in US policy towards Moscow.

European leaders have convened a series of meetings in response, aimed both at showing the US that Europe can do more to support Ukraine militarily, as well as providing a single voice urging the US president not to take Russia’s side in the war.

For its part, rather than commit to a lengthy ceasefire, the Kremlin has instead pursued a policy of unilateral short-term ceasefires – the latest of which began on Thursday and is due to end at midnight tonight.

It coincided with Russia’s May 9 Victory Day celebrations – when the country marks the defeat of Nazi Germany. This year, Chinese President Xi Jinping and Brazilian leader Luiz Inácio Lula da Silva were among Putin’s guests attending the annual parade in Moscow.

Ukraine has reported many hundreds of Russian attacks along frontline locations during the ceasefire period, though missile and Shahed drone attacks on Ukraine’s cities have not been seen since Wednesday.

In a rare – though not unprecedented – move, the US embassy in Kyiv issued a security alert on Friday warning it had intelligence suggesting a possible “significant air attack that may occur at any time over the next several days.”