PUTIN is feared to be plotting a massive airstrike on Kyiv where world leaders have gathered “at any time”, according to US intelligence.

Keir Starmer, France‘s Emmanuel Macron, new German chancellor Friedrich Merz, and Polish premier Donald Tusk, are all in the Ukrainian capital today.

The three-day ceasefire Putin announced is due to end tonight – while the leaders will still be in Kyiv.

And Ukraine has accused Russia of already breaching the truce numerous times with bomb raids and gunfire.

American officials felt compelled to release a public alert stating: “The US Embassy in Kyiv has obtained information about a potentially significant air attack that could occur at any time over the next few days.”

“The Embassy, as always, recommends US citizens be prepared to immediately shelter in the event an air alert is announced.”

Western leaders have rallied around President Zelensky in a display of solidarity, with more than 20 of them having traveled to Moscow on Friday for Russia’s massive Victory Day parade.

The four from the UK, France, Germany and Poland arrived together at Kyiv’s train station, presenting a united front in their calls for peace.

A similar warning was issued on November 20 last year – one day before Russia struck Dnipro with an Oreshnik ballistic missile.

Intelligence has disclosed that Russia intends to close the airspace over its Kapustin Yar missile test site between 6:00 am on Monday and 6:00 am on Tuesday.

This is the same site that launched the Oreshnik on Dnipro last year – and so could signal Russia is plotting similar assault.

Any fresh Russian strike will mark the failure of major recent efforts to force Putin into a longer, 30-day ceasefire.

Zelensky has long pushed for an extended truce to create a window for a full peace agreement.

But Putin has shown few signs of any desire to halt the war.

Chancellor Merz was hopeful that an agreement was within reach, amid threats of huge new sanctions against Russia.

He said: “I have great hope that a ceasefire agreement in Ukraine will be reached this weekend.

“Now the ball is in Moscow‘s court.”

Donald Trump demanded: “I have a message to both sides: end this war.

“We are losing 5,000 soldiers a week, Russian and Ukrainian soldiers, and other people, and I say: end this stupid war. This is my message to both sides.”

The Kremlin fell back on its stalling tactics, with spokesman Dmitry Peskov saying that Putin demanded “certain dynamics” on the battlefield before agreeing an extended ceasefire.

Most notably, the Russian want the West to stop military supplies to Kyiv.

Peskov said: “Otherwise, it will be [advantageous] for Ukraine.

“Ukraine will continue their total mobilisation, bringing new troops to [the] front line.

“Ukraine will use this period to train new military personnel and to give a rest to their existing ones.

“So why should we grant such an advantage to Ukraine?”

Despite Zelensky’s continued pleas for peace, Peskov accused Kyiv of being “not ready for immediate negotiations”.

Denying the Kremlin was dragging its feet, he claimed: “President Putin is doing whatever is possible to solve the problem, to achieve a settlement through peaceful and diplomatic means.

“But having no peaceful and democratic means at hand, we have to continue [the] military operation.”

Trump has also throw his weight behind a 30-day unconditional ceasefire.

He said: “Hopefully, an acceptable ceasefire will be observed, and both countries will be held accountable for respecting the sanctity of these direct negotiations.”

European leaders – including Starmer – said in a statement before arriving in Kyiv: “The bloodshed must end, Russia must end its illegal invasion, and Ukraine must be allowed to flourish as a secure and independent nation within its internationally recognised borders for generations to come.

“We intend to continue to increase our support for Ukraine.

“We will increase pressure on the Russian war machine until Russia agrees to a permanent ceasefire.”

The leaders vowed to reaffirm to Zelensky their unwavering support.

The joint statement continued: “We, the leaders of France, Germany, Poland and Britain, stand in Kyiv in solidarity with Ukraine against Russia’s barbaric and illegal full-scale invasion.”

Three Ukrainian civilians were killed in the Sumy region by Russian strikes on May 8 and 9 – despite the supposed ceasefire.

Russian media has reported in recent days that Putin had given the go-ahead to a new Oreshnik strike.

Kremlin-friendly Mash said three days ago:“Vladimir Putin gave the Russian Defence Ministry instructions to identify targets in Kyiv for the Oreshnik strike.”

A similar report was carried by Baza, also close to the Kremlin.

Oreshnik is nuclear-capable, but Putin threatens it is almost as destructive with non-nuclear warheads.

Targets would be incinerated, he said, with the weapons unleashing a temperature of 4,000 degrees – almost as hot as the surface of the sun.

Russia hit Ukrainian city Dnipro with a fearsome Oreshnik missile in November 2024 in revenge for the use of UK and US missiles against his territory.