Donald Trump has reopened a diplomatic fault line between Washington and London, urging Britain not to proceed with its plan to hand sovereignty over the Chagos Islands to Mauritius and lease back Diego Garcia, a strategically important military base used by US and British forces.
In a sharply worded social media post on Wednesday, the US president warned that the leasing deals were “no use when it comes to countries” and suggested the deal could weaken Britain’s control over a key Indo-Pacific base at a time of heightened tensions with Iran.
Read also | The UK is investigating whether Trump has the power to derail the Chagos deal
The intervention comes despite the US State Department formally approving the deal between Britain and Mauritius just a day earlier, underscoring the erratic reporting that has defined Trump’s foreign policy.
Why Trump Said “Don’t Give Diego Garcia Away”
Trump called the planned handover a strategic mistake and a political embarrassment for the UK, calling it an unnecessary concession that could undermine a close ally.
“Don’t give Diego Garcia away,” he wrote, criticizing the UK’s plan to give up sovereignty and lease back the base.
He added that “this country should not be taken away from the UK” and warned that if it were, it would be “a danger to our Great Ally”.
The post, published on Truth Social, was specifically aimed at Prime Minister Keir Starmer, with Trump arguing that Britain would lose influence by accepting a long-term lease rather than retaining full sovereignty.
“I told UK Prime Minister Keir Starmer that leases are not good for land and that he made a big mistake when he signed a 100 year deal…” Trump wrote.
Why Diego Garcia is important to the US and UK
Diego Garcia, the largest island in the Chagos archipelago, hosts one of the most important military installations in the Indian Ocean. It is operated as a joint base for the US and UK armed forces and is widely regarded as a mainstay of operations in the Middle East, East Africa and the Indo-Pacific.
Trump emphasized the base’s geography, describing it as “strategically located in the Indian Ocean.”
He argued that Starmer was “losing control of this important island to the claims of entities hitherto unknown”, a reference to Mauritius’ long-standing legal and diplomatic challenge to British sovereignty.
Trump also linked Diego Garcia to a potential military escalation with Iran, citing ongoing talks about Tehran’s nuclear program.
Read also | Where are the Chagos Islands? What is the agreement between the UK and Mauritius? What is India’s position?
“If Iran chooses not to make a deal, it may be necessary for the United States to use Diego Garcia … to root out a potential attack by a highly unstable and dangerous Regime,” he wrote.
The Republican president has repeatedly threatened military action against Iran over its nuclear activities and its crackdown on protests. American and European allies suspect Iran of moving towards developing a nuclear weapon, which Tehran has always denied.
UK agreement with Mauritius: 99-year leaseback and transfer of sovereignty
The deal, which is at the center of Trump’s criticism, was announced last May. Under its terms, the UK would cede sovereignty of the British Indian Ocean Territory – commonly known as the Chagos Islands – to Mauritius, while leasing back Diego Garcia for 99 years.
Starmer has previously argued that the agreement is necessary to protect the continued operation of the base, particularly in light of repeated legal challenges to British control of the islands.
The Chagos Islands have been under British control since 1814 and were established as an overseas territory in 1965. However, Mauritius has long argued that it was illegally forced to give up the islands as part of the terms for independence.
Read also | ‘Stupid act’: Trump slams UK over Chagos deal, Britain hits back
In the late 1960s, Britain invited the United States to build a military base on Diego Garcia, forcibly removing thousands of Chagossians from their homes. Many were resettled in Mauritius and the Seychelles, while others later moved to the UK, particularly to Crawley in West Sussex.
US policy: The State Department endorsed the deal a day earlier
Trump’s intervention is politically inconvenient for Starmer not only because he comes from Washington, but also because it contradicts the official US position expressed earlier this week.
On Tuesday, the US State Department said it “supports the UK’s decision to continue the agreement with Mauritius on the Chagos Islands”.
The confirmation was meant to remove doubts about whether the US military would remain secure under the lease-back deal. Trump’s post instead revived questions about whether the White House and State Department are aligned.
Asked about the president’s remarks, White House press secretary Karoline Leavitt said the post should be considered official policy.
“The post should be taken as Trump administration policy, coming straight from the horse’s mouth.”
Read also | Britain signs a multibillion-dollar agreement between the Chagos and Mauritius
“When you see it on Truth Social, you know it’s straight from President Trump, that’s the beauty of this president in his transparency and delivery of the policies of this administration.”
UK response: “critical to the security of the UK and our key allies”
Britain quickly sought to defend the deal, calling it a security measure rather than a diplomatic concession.
Responding to Trump, the Foreign Office said the Chagos deal was “vital to the security of the UK and our key allies and to keeping the British people safe”.
“The agreement we have reached is the only way to guarantee the long-term future of this vital military base,” it said.
Officials argued that the arrangement was preferable to long-term legal uncertainty that could jeopardize the base’s operations.
Trump’s deeper objection: sovereignty, not logistics
Trump’s criticism isn’t just about the length of the lease. It stems from his broader view that long-term leases signal weakness and invite future disputes — a worldview shaped by his background in development and his preference for maximum leverage in negotiations.
The US president argued that Britain had made a mistake by giving up sovereignty and relying on the lease to secure continued access. He also framed the issue through the lens of culture-war politics.
Read also | Chagos: Why India is supporting a cause the world has forgotten
“We will always be ready, willing and able to fight for the UK, but they must remain strong in the face of wakeism and the other challenges ahead,” he wrote.
The language signaled that Trump sees the dispute not only as a matter of strategy but also as part of his broader criticism of liberal governance in allied capitals.
British politics: Starmer accused of weakness as rivals seize on Trump attack
The US president’s post immediately sparked a new wave of domestic criticism, with opposition parties portraying it as evidence that the British approach had failed.
Shadow Foreign Secretary Priti Patel called the remarks “absolute humiliation” for Starmer.
“It’s time for Starmer to finally see sense, turn around and scrap this appalling deal completely,” she said.
Liberal Democrat leader Ed Davey claimed the episode showed the UK could not depend on Washington while Trump remained in office.
“Trump’s endless hopping on the Chagos Islands shows why Starmer’s approach is doomed to failure,” he wrote on X.
Read also | United Kingdom hands over Chagos Island to Mauritius; India Says “Welcome Development”
“Britain cannot rely on the US as long as Trump is in the White House. It is time to strengthen our relationships with allies we can rely on, starting with our neighbors in Europe.”
Reformist UK leader Nigel Farage, a long-time critic of the handover, welcomed Trump’s intervention.
“Keir Starmer risks alienating our most important ally by giving away the Chagos Islands, the worst deal in British history,” he wrote on X.
“President Trump is right when he says the prime minister is making a big mistake. Starmer needs to cancel this deal.”
The Chagos protest is growing as the deal faces increasing scrutiny
A political dispute develops along with renewed protest from the Chagossians themselves. Earlier this week, four Chagos islanders who opposed the handover landed on the remote atoll as part of a protest and refused to leave, despite threats of eviction by the British maritime patrol.
The protest reflects a long-standing grievance: that the Chagossans have been displaced to allow for a US base, and that sovereignty decisions are being made without their consent.
What happens next: US-Mauritius talks and growing uncertainty
Trump’s comments come ahead of talks between the United States and Mauritius planned for next week, raising the risk that the dispute will spill over into formal diplomacy.
The US president’s stance has also shifted repeatedly in recent months, from calling the transfer an “act of great stupidity” to suggesting it was the “best” deal Starmer could have done – and now reverting to outright opposition.
The immediate challenge for Britain is to keep the deal on track while reassuring Washington that the base remains secure. For the United States, the deeper question is whether the State Department—or the last post of the president—determines official administration policy.