Srinagar: Russian President Vladimir Putin and his US counterpart Joe Biden have agreed to a summit to be held only if Moscow does not invade Ukraine, reported news agency AFP.

According to the news agency, both leaders have said yes in principle to the summit, proposed by French President Emmanuel Macron, his office said, with the White House confirming Biden’s willingness, though it was notably cautious.

A senior administration official told AFP: “Timing to be determined. Format to be determined so it’s all completely notional.”

The Elysee added that the summit will be expanded to “relevant stakeholders” and that preparations would start between Russia and the United States on Thursday.

The possible breakthrough came after Washington warned of an imminent invasion and Ukraine and Russia blamed each other for a spike in shellings on the front line separating Kyiv’s forces from Moscow-backed separatists the report said.

The bombardments have sent Ukrainians fleeing to cellars and other shelters, while some civilians have been evacuated, the report said..

In its own statement, the White House warned that it was still ready “to impose swift and severe consequences” should Russia invade.

“And currently, Russia appears to be continuing preparations for a full-scale assault on Ukraine very soon,” US press secretary Jen Psaki said according to the report.

Washington and other Western capitals say that Russia has massed more than 150,000 troops on Ukraine’s borders and is ready to launch a full-scale assault.

Moscow denies any intention to invade its neighbour, but has demanded that the NATO alliance permanently rule out Ukraine’s bid for membership and called for the withdrawal of Western forces deployed in eastern Europe since the end of the Cold War.

The announcement of the summit came moments after Macron held his second marathon call with Putin of the day.