United States President Donald Trump has sharply criticised the United Kingdom’s plan to transfer sovereignty of the Chagos Islands to Mauritius — just one day after his administration formally approved the agreement.
In a fiery post on Truth Social, Trump warned British Prime Minister Keir Starmer that he was “making a big mistake.”
“DO NOT GIVE AWAY DIEGO GARCIA!” Trump wrote, referring to the strategically vital island that hosts a joint UK-US military base.
What the Deal Includes
Under the agreement, the UK will transfer sovereignty of the Chagos archipelago to Mauritius while maintaining a 99-year lease — with an option to extend — on Diego Garcia.
The lease is expected to cost the UK roughly £100 million ($135 million) annually.
Diego Garcia remains one of the most important military outposts in the Indian Ocean, used for operations ranging from Afghanistan in 2001 to more recent actions against Houthi targets in Yemen.
Trump warned that long-term leases are “no good when it comes to Countries” and argued that the base could be critical in countering any future threat from Iran.
“It may be necessary for the United States to use Diego Garcia,” he wrote, calling the lease arrangement “tenuous.”
A Diplomatic Reversal
The criticism comes just a day after the US Department of State publicly backed the agreement.
“The United States supports the decision of the United Kingdom to proceed with its agreement with Mauritius,” the department said in a statement.
That apparent contradiction adds another twist to what has already been described as a diplomatic rollercoaster between Washington and London.
Trump previously called the deal an act of “great stupidity” earlier this year, then later said he understood it may have been the best arrangement Starmer could secure — while reserving the right to “militarily secure” the base if necessary.
The Legal Battle Behind the Transfer
The Chagos Islands were originally administered as part of Mauritius during French control before the UK took possession in the early 19th century.
In 1968, before granting Mauritius independence, Britain detached the Chagos Islands and later forcibly displaced up to 2,000 Chagossians to establish the Diego Garcia base.
In 2019, the International Court of Justice ruled that the UK should cede control of the islands. The ruling was followed by a UN resolution urging Britain to return the territory within six months.
The UK government says it had little choice but to negotiate a settlement after international legal pressure threatened its ability to operate the base under previous arrangements.
A spokesperson for the UK’s Foreign, Commonwealth and Development Office said the deal is “crucial to the security of the UK and our key allies.”
“The agreement we have reached is the only way to guarantee the long-term future of this vital military base,” the spokesperson added.
Strategic Stakes: Iran and Regional Security
Trump linked the deal directly to escalating tensions in the Middle East, suggesting Diego Garcia and RAF Fairford in the UK could be used in response to a potential Iranian attack if nuclear negotiations fail.
“You can’t disassociate Iran from the Middle East or the Middle East from Iran,” one diplomat noted in discussions surrounding the broader regional climate.
Diego Garcia’s location makes it a critical logistics and strike hub for US and UK forces — a factor that continues to drive debate over who ultimately controls the island.
Chagossian Concerns
While Mauritius celebrated its legal victory, some displaced Chagossians have criticised the agreement, accusing Mauritius of neglecting their interests — claims the Mauritian government denies.
The forced removal of islanders in the 1960s and 1970s remains one of the most controversial chapters in the territory’s history.
What Happens Next?
The UK will proceed with its 99-year lease arrangement, and US-Mauritius talks are scheduled in the coming weeks.
But Trump’s public intervention signals that the political debate — particularly around security and sovereignty — is far from settled.
At the center of it all lies a small island in the Indian Ocean, carrying outsized importance for global military strategy.
And for now, Diego Garcia remains both a symbol of alliance — and a flashpoint of disagreement.
