The British government on Tuesday defended its agreement to transfer sovereignty of the Chagos Islands to Mauritius, insisting the deal secures the long-term future of a strategically vital US-UK military base, after US President Donald Trump sharply criticised the move.
Trump described the handover as an act of “great stupidity” in a post on his Truth Social platform, marking a significant shift from his earlier position. The US president had previously endorsed the agreement when it was signed in May 2025.
“The UK giving away extremely important land is an act of GREAT STUPIDITY,” Trump wrote, linking the issue to his renewed calls for the United States to acquire Greenland. His comments followed recent threats to impose tariffs on Britain and other European countries over their opposition to US claims on Greenland.
In response, Downing Street said the Chagos agreement guarantees the continued operation of the joint US-UK military base on Diego Garcia, the largest island in the archipelago, which Britain will lease back for nearly a century.
“This deal secures the operations of the joint US-UK base on Diego Garcia for generations, with robust provisions for keeping its unique capabilities intact and our adversaries out,” a UK government spokesperson said. The spokesperson added that the agreement has been welcomed by the United States, Australia and other Five Eyes partners, as well as key allies including India, Japan and South Korea.
US Secretary of State Marco Rubio had earlier described the pact as a “historic agreement,” saying the Trump administration determined it would ensure the stable and effective long-term operation of the military facility. UK Cabinet Office minister Darren Jones said the treaty had already been signed and could not be reversed.
Britain retained control of the Chagos Islands after Mauritius gained independence in the 1960s but forcibly removed thousands of islanders, who later pursued compensation through British courts. In 2019, the International Court of Justice advised the UK to return the territory to Mauritius following decades of legal disputes.
The UK government has argued that continued legal challenges in domestic and international courts had placed the future of the Diego Garcia base at risk, making the agreement necessary.
However, the deal has drawn criticism at home. Under its terms, Britain will pay Mauritius £101 million annually for a 99-year lease of Diego Garcia, with the total cost estimated at about £3.4 billion when inflation is considered.
Opposition Conservative leader Kemi Badenoch said she agreed with Trump’s criticism, while Reform UK leader Nigel Farage praised the US president for opposing what he described as the “surrender” of the islands. In contrast, Liberal Democrat leader Ed Davey urged Prime Minister Keir Starmer to take a firmer stance against Washington, warning that efforts to appease Trump were proving ineffective.
