Footage has emerged of Donald Trump mocking Keir Starmer by claiming the prime minister said he would have to consult his team before deciding whether to send UK aircraft carriers to the Middle East.

In a new low for UK-US relations, Trump appeared to impersonate Starmer during an Easter lunch speech at the White House.

The US president said the UK “should be our best” ally but had not been during the Iran war, accusing Starmer of prevaricating over sending aircraft carriers.

However, Whitehall sources said Trump had never asked the UK for the vessels and Britain had not offered them.

During his speech, the president said: “I asked [the] UK, who should be our best. In fact the king is coming over here in two weeks, he’s a nice guy, King Charles.

“But should be our best but they weren’t our best. I said: ‘You have two, old broken-down aircraft carriers, do you think you could send them over?’

“‘Ohhh, I’ll have to ask my team.’

“I said: ‘You’re the prime minister, you don’t have to.’

“‘No, no, no, I have to ask my team. My team has to meet, we’re meeting next week.’

“But the war already started. Next week the war’s going to be over … in three days.”

The remarks were made at a lunch that was not open to the press. It was released by the White House on a social media channel but later deleted. However, it was downloaded and republished by a politics reporter for the US website Business Insider.

During the lunch, Trump also mocked Emmanuel Macron, saying the French president was “still recovering from the right to the jaw” and claimed that Macron’s wife, Brigitte, “treats him extremely badly”.

Trump has repeatedly hit out at the UK over its decision not to authorise the use of military bases for the initial strikes on Iran, as well as the move to hand sovereignty of the Chagos Islands to Mauritius.

Starmer has not retaliated but said he would stick to his position on the war “whatever the pressure and the noise”.

When asked previously at parliament’s liaison committee about the “quite rude” comments made by Trump about him, the prime minster said: “I’m utterly focused on what is in the best interests of our country and I am unapologetic about that.

“Notwithstanding the pressure that comes from elsewhere, I will remain laser focused on what is in the British national interest.

“And a lot of what is said or done is undoubtedly said and done to put pressure on me, I have no doubt about that. I understand what is going on. But I am not going to be wavering on this.”

He added: “I am the British prime minister and my job is to be absolutely focused on what is in the British national interest. That has served me well in recent weeks and that is the principle that I will continue to adhere to as we go forward taking difficult decisions.”