The UK has not agreed to allow the US to launch air strikes against Iran from a British base on Diego Garcia and another in Gloucestershire, it is understood.
The Times first reported the lack of permission.
The newspaper said, as a result of the UK’s reticence, Donald Trump had withdrawn his support for a deal struck by Sir Keir Starmer to hand the Chagos Islands, which include Diego Garcia, over to Mauritius.
US military plans to strike Iran involve the use of a British and American military base on Diego Garcia as well as RAF Fairford in Gloucestershire, which hosts a US fleet of heavy bombers.
Under long-standing agreements between London and Washington, the Pentagon is only able to launch operations from the two sites, as well as other air bases in the UK that are home to US warplanes and personnel, with advance approval from the British government.
This has not yet been given in relation to any potential strike against Iran because of concern that such a mission would be a breach of international law, according to The Times.
President Trump on Thursday said the world would find out “over the next, probably, 10 days” whether the US would reach a deal with Iran to end its nuclear ambitions – or take military action.
He has been surging forces to the Middle East – including two giant aircraft carriers and supporting warships and jets – to increase his options for launching a significant military operation against the Islamic Republic should talks fail.
Mr Trump spoke on Tuesday evening by phone with the British prime minister. The topics covered included the Iran crisis, but not the Chagos Islands.
However, the following day, the president launched a new attack on Mr Starmer over the Chagos Islands deal, even after his own State Department had said it supported the UK’s decision to give the territory to Mauritius and lease back Diego Garcia.
In a post on social media, Mr Trump explicitly mentioned the utility of Diego Garcia and Fairford for US military operations against Iran, and appeared to suggest why it would be within international law for the UK to grant such deployments, given that it too could be under threat.
“Should Iran decide not to make a Deal, it may be necessary for the United States to use Diego Garcia, and the Airfield located in Fairford, in order to eradicate a potential attack by a highly unstable and dangerous Regime” Mr Trump wrote on his Truth Social site.
“An attack that would potentially be made on the United Kingdom, as well as other friendly countries.”
He then said: “We will always be ready, willing, and able to fight for the UK, but they have to remain strong in the face of Wokeism, and other problems put before them.”
Read more:
Why is the Chagos Islands deal controversial?
Trump to PM: ‘Do not give away Diego Garcia’
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The UK is not thought to be preparing to support the US in any military offensive against Iran.
However, the Royal Air Force has deployed six F-35 warplanes to RAF Akrotiri on Cyprus, and sent four Typhoon jets to Qatar, as part of efforts to bolster its own defences in the event of any Iranian counterattack in response to American strikes.
On the Chagos Islands deal, the government has repeatedly defended its decision to hand over the territory to Mauritius, saying it would avoid a costly legal battle while securing access to Diego Garcia for 100 years.
