Donald Trump has told The Telegraph he is “very disappointed” in Sir Keir Starmer for blocking him from using Diego Garcia to carry out strikes on Iran.

In an exclusive interview, the US president said that the Prime Minister’s initial refusal to let US forces use the Chagos Islands base was unlike anything that had “happened between our countries before”.

Britain had denied the US permission to conduct strikes from bases such as Diego Garcia and RAF Fairford, citing international law. However, the Prime Minister relented on Sunday night and said he would allow the US access to Diego Garcia for “specific and limited defensive purposes”.

Mr Trump said Sir Keir “took far too long” to change his mind.

“That’s probably never happened between our countries before,” he told The Telegraph, adding: “It sounds like he was worried about the legality.”

The row over Diego Garcia led the president to withdraw his support for the Prime Minister’s controversial Chagos deal to hand over ownership of the Indian Ocean territory to Mauritius and instead lease back the military base.

Mr Trump told The Telegraph: “All of a sudden [Mauritius] was claiming ownership. He should have fought it out and owned it or make him take it, if you want to know the truth. But no, we were very disappointed in Keir.”

Two days into the US strikes on Iran, the president said the operation was “well ahead of schedule”.

Mr Trump suggested Sir Keir should have always approved American use of Diego Garcia, because Iran was responsible for killing “a lot of people from your country”.

“[There are] people without arms and legs and faces that have been blown up. Iran is 95 per cent of those. Those horrible events were caused by Iran,” Mr Trump said, without referring to specific cases.

Mr Trump told The Telegraph the Chagos deal was “a very woke thing”.

“It would have been much better on the legal front if he just kept the ownership of the land and not given it to people that weren’t the rightful owners,” he said.

Referring to Sir Keir’s about-turn on Diego Garcia, he added: “It is useful. It took far too much time. Far too much time.”