Sir Keir Starmer defended not allowing the Chagos Islands to be used by the US in the first strikes on Iran.
Trump claimed the Prime Minister was ‘worried about the legality’ of the strikes that wiped out Iran’s supreme leadership, killing Ayatollah Ali Khamenei.
The Prime Minister finally granted permission on Sunday for the US to use British bases to target Iran’s missile launchers and stores to help protect countries targeted by Tehran.
But the US president said he was ‘very disappointed’ in Sir Keir for initially refusing to allow the use of the UK-US Diego Garcia base to target Iran.
‘That’s probably never happened between our countries before,’ he told The Telegraph, adding: ‘It sounds like he was worried about the legality.’
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Mr Trump said it ‘took far too long’ for the Prime Minister to change his mind.
In a Commons statement, Sir Keir said: ‘President Trump has expressed his disagreement with our decision not to get involved in the initial strikes, but it is my duty to judge what is in Britain’s national interest.’
The US had sought the use of the Diego Garcia base in the Indian Ocean and RAF Fairford in Gloucestershire for strikes against Iran.
Referring to Sir Keir’s change of position, Trump added: ‘It is useful. It took far too much time. Far too much time.’
In a statement to MPs, Sir Keir said ‘that decision was deliberate’ and ‘I stand by it’.
He said that ‘we all remember the mistakes of Iraq’ adding ‘any UK actions must always have a lawful basis and a viable thought-through plan’.
In an apparent criticism of the US approach, he said: ‘This government does not believe in regime change from the skies.’
But Iran’s retaliation to the US and Israeli attacks had threatened British people across the Middle East, prompting the decision to allow the bases to be used to hit Tehran’s missile infrastructure.
‘It is clear that Iran’s outrageous response has become a threat to our people, our interests, and our allies and it cannot be ignored,’ he said.
Westminster insiders said attempting to strike Iran’s ballistic missiles once they were in flight was like trying to knock an ‘arrow’ out of the sky, but the US had been given permission to use British bases to go after the ‘archer’ – the launch sites and storage silos.
Iran has hit targets across the Middle East, including in the United Arab Emirates, Qatar and Saudi Arabia, and there are fears Tehran has the ability to keep up its retaliatory actions for a week.
Around 300,000 Britons are believed to be in countries targeted by Iran, with 102,000 registering their presence with the Foreign Office as officials worked on contingency plans including a possible mass evacuation.
Sir Keir said the Government is ‘looking at all options to support our people’.
Hours after Sir Keir’s announcement on Sunday about allowing the US use of bases, a drone hit RAF Akrotiri in Cyprus.
Sir Keir said the drone was launched before his announcement and was not in retaliation to it.
Defence Secretary John Healey said there were no casualties and the damage to the base was minimal.
The families of service personnel have been moved away from the base as a precaution.
On Monday, a spokesperson for the Cypriot government said two further unmanned drones heading towards the base had been intercepted.
Mr Healey said the drone, which hit Akrotiri, was an example of the ‘dangerous and indiscriminate attacks’ by Iran and its proxies.
Tory leader Kemi Badenoch claimed the Government’s reluctance to allow US forces to use UK bases was because Labour wanted to avoid alienating voters ‘whose political loyalties are swayed by conflicts in the Middle East, not the British national interest’.