It is seen as the latest in a series of potentially dangerous missteps in recent weeks.

A month before the war, the 79-year-old president suggested Russia would face minimal consequences if it restrained itself to a “minor incursion”.

Mr Biden suggested last week that Nato would respond “in kind” if the Kremlin deployed chemical weapons. He also called Putin a “war criminal” after hurriedly changing his mind during an exchange with a reporter. 

At the weekend, he told US troops in Poland that they would witness the bravery of Ukrainian soldiers “when you’re there” – forcing the White House to quickly clarify that American soldiers were not being sent over the border.

Rebuking his US counterpart, Mr Macron, the French president, said on Sunday: “I think we must do everything to avoid the situation getting out of hand. I wouldn’t use these kinds of words because I’m still in talks with President Putin.”

Mr Macron said the “collective goal” was to stop the war “without escalating things”.

He said his duty as French president was not to pursue regime change but to “take the diplomatic path in order first to obtain a ceasefire and then a total withdrawal of troops”.

Gaffes ‘three, four times a day’

Antony Blinken, the US secretary of state, contradicted his president, telling a press conference in Jerusalem: “As you know, and as you’ve heard us say repeatedly, we do not have a strategy of regime change in Russia or anywhere else, for that matter. In this case, as in any case, it’s up to the people of the country in question. It’s up to the Russian people.” 

The US envoy to Nato suggested that Mr Biden had become emotionally charged after hearing the “heroic stories” of Ukrainian refugees in Poland who had fled “Russia’s brutal war”. Julianne Smith told CNN: “In the moment, I think that was a principled human reaction to the stories that he had heard that day. But no … the US does not have a policy of regime change in Russia. Full stop.”

A Downing Street spokesman said that regime change was not a policy being pursued by Boris Johnson and echoed comments made by Nadhim Zahawi earlier. The Education Secretary said in a television interview that it was “for the Russian people to decide how they are governed”, adding: “I think the Russian people will decide the fate of Putin and his cronies.”

Mr Trump, who is expected to run for the presidency in 2024, said his successor risked provoking Putin into using nuclear weapons. 

“When you put him into a corner and you talk the way they’re talking … they’re almost giving him an incentive,” said Mr Biden’s predecessor. The Kremlin’s spokesman last week said that Russia could use nuclear weapons if it faced an “existential threat”, while analysts note that Putin increasingly considers himself to be the embodiment of the Russian state. 

Mr Trump said Mr Biden was being forced to apologise “three, four times a day” for gaffes, adding: “We have people that don’t know what they’re doing. And it’s the most dangerous time in the history of our country, in my opinion.”

Mr Biden’s apparent call for regime change appeared to stiffen resolve in Moscow to back Putin.

Vyacheslav Volodin, chairman of the Duma, Russia’s lower house of parliament, said: “This is how a weak and sick person behaves – psychiatrists will be able to explain his behaviour better. American citizens should be ashamed of their president.”

In the US, there was a recognition that Mr Biden had made a serious error of judgment.

Richard Haass, an American diplomat who heads the Council on Foreign Relations, said on Twitter: