FEBRUARY 26, 2026
Donald Trump has urged Sir Keir Starmer, pictured together in September 2025, not to ‘give away Diego Garcia’ – Leon Neal/Pool via REUTERS
Donald Trump is refusing to back Sir Keir Starmer’s Chagos deal again unless the Prime Minister allows the US to use the islands to strike Iran.
The US president is understood to have asked to use Diego Garcia, the joint US-UK base on the islands, in the event that America decides to launch strikes on Iran.
He has repeatedly threatened to take military action unless the country’s leaders sign a deal with the US to curb its nuclear programme.
However, Downing Street is concerned that supporting any such strikes by Mr. Trump would breach international law.
Whitehall sources told The Telegraph that the White House was refusing to change its stance on the Chagos deal, which will see the UK give the islands away to Mauritius, until Britain allows the US to use the base.
The US president is understood to have asked to use Diego Garcia in the event of a war with Iran – Handout / DoD/AFP via Getty Images
Last week, Mr Trump said Sir Keir should not “give away Diego Garcia”, in a rapid about-turn from his previous support for the deal.
On Wednesday, a minister admitted that the deal had been “paused” while Britain continued discussions with the US, because it could not go ahead without American consent.
It was previously reported that although the US requires permission to use British military bases in the UK, the Pentagon has free rein on Diego Garcia because it is a joint facility governed by a 1966 exchange of diplomatic notes between London and Washington.
However, The Telegraph understands that the Foreign Office has a veto on American use of the base if the US military strays from “normal” operations.
Government lawyers believe that using the base to strike Iran would be covered by a separate clause on “other circumstances”, which says that both the US and UK must agree on an operation before it takes place.
Mr Trump’s previous strike on Iranian nuclear facilities in June 2025 did not use Diego Garcia. Instead, US air force bombers were flown to the Middle East from Utah.
US and Israeli forces carried out a string of bombing raids on Iran in June 2025 – SOCIAL MEDIA via REUTERS
But it is understood that US plans for a second set of strikes include a more sustained bombing campaign using aircraft with a shorter range, which would require a base closer to the targets.
A third of the US navy has travelled to waters near Iran, which is refusing to scale back its nuclear programme despite threats from the president.
On Tuesday, during his State of the Union address, Mr. Trump appeared to lay out his legal and political case for action.
In the speech, the president accused Iran of building missiles that could reach the US, threatening its national security.
“We are in negotiations with them. They want to make a deal, but we haven’t heard those secret words: ‘We will never have a nuclear weapon’,” he said.
The Foreign Office declined to comment on whether permission for the US to use Diego Garcia had been sought or denied.
Mr Trump has changed his mind three times about the Chagos deal, after intense lobbying from the UK and US intelligence community and Republicans on Capitol Hill.
Britain argues that giving away the islands to Mauritius and renting back Diego Garcia at a cost of £35bn for 99 years is the only way to protect it from legal challenges in the international courts, which ministers say would endanger the operation of the base.
But critics say the deal would bring the base within China’s military orbit and leave it vulnerable to malign influence.
John Kennedy, a Republican senator for Louisiana, is understood to have raised the issue with senior members of the administration, including Marco Rubio, the US secretary of state.
Also credited with putting the deal in the president’s in-tray are Scott Bessent, the US treasury secretary, and Nigel Farage, the Reform UK leader.
Ministers had hoped to ratify the treaty underpinning the deal with Mauritius by the end of last year, but the process has been repeatedly delayed by changes in the US position.
Shortly after taking office, Mr. Trump said he supported the deal and believed it would help the base – a stance lauded by British officials as a diplomatic victory.
He changed his mind on Jan 20, arguing it was an act of “great stupidity” by the UK, before reversing his position for a second time 10 days later, when he said it was the “best” deal Sir Keir could have struck in the circumstances.
Mr. Trump then returned to opposing the deal last week, writing on his Truth Social platform that “this land should not be taken away from the UK” and that a giveaway to Mauritius would be “a blight on our Great Ally”.
It is understood that the latest change in Mr. Trump’s position came after conversations between British and American officials about the prospect of bombing runs between Diego Garcia and Iran. UK government lawyers believe such action could be illegal.
Mr. Trump, pictured with Sir Keir in September 2025, has changed his stance on the Chagos deal several times – NEIL HALL/POOL/EPA/Shutterstock
Under a UN ruling from 2001, legal action can be brought against a state that conducts an illegal strike and against any other state with “knowledge of the circumstances of the internationally wrongful act”.
Last week, The Times reported that Mr. Trump criticized the deal after the UK refused to let him use British bases to strike Iran.
Since then, The Telegraph understands that American officials have held firm, telling Downing Street and the Foreign Office that the White House’s support for the deal will not return unless permission is given.
US officials have also demanded confirmation in writing that America will not be required to tell Mauritius about attacks launched from the base after the sovereignty of the islands is transferred.
The UK has always argued that there would be no “notification” requirement under the text of the deal signed by Sir Keir last May, but US government lawyers are not convinced of that claim.
Ministers are now concerned that it will not be possible to resolve the situation before the end of a 10-week deadline to return the Chagos bill – legislation that underpins the deal – to Parliament for the approval of MPs.
On Thursday, Downing Street said “discussions are indeed continuing” with the US but denied that the deal had been “delayed”, as a minister said in the Commons on Wednesday.
Sir Keir’s official spokesman said: “There is no pause. We have never set a deadline. That is the position.”
Baroness Chapman, a Foreign Office minister, told Parliament that the Government had previously “secured very clear and firm support” from the White House for the transfer agreement and was holding “close, intense conversations with our dearest allies and partners about the consistency of this decision”.
If the legislation does not make it through Parliament before the end of the current session, ministers will have to reintroduce the bill from scratch after the King’s Speech on May 12 or 13.
Without approval from the US, Sir Keir will have to decide whether to continue with the deal in defiance of Mr. Trump, or abandon it entirely, which would likely trigger a multi-billion-pound legal challenge from Mauritius.
Courtesy/Source: This Telegraph
