U.S. President Donald Trump has reportedly reversed a recent objection to a British plan to transfer sovereignty over the Chagos archipelago to Mauritius, after days of intensive diplomacy and new assurances about the future of the U.S. military base on Diego Garcia. The apparent change of heart follows a brief period of public opposition from Mr. Trump that threatened to derail an agreement signed in London last year by Prime Minister Keir Starmer.
The Chagos group sits roughly 750 kilometres northeast of Mauritius in the southwest Indian Ocean and has been at the centre of a long-running post-colonial dispute. In 1965 Britain separated the islands from Mauritius; in 1966 it leased the main island, Diego Garcia, to the United States for a military base and expelled about 2,000 islanders. On May 22, 2025, Mr. Starmer signed a treaty to transfer sovereignty to Mauritius while preserving the base through a leaseback arrangement to the UK and the United States.
Mr. Trump initially indicated he might approve the deal when Mr. Starmer visited Washington, but in January he publicly denounced the transfer as “extremely stupid,” invoking the episode as evidence for his argument that the United States should secure strategic territories such as Greenland. British officials then mounted an urgent diplomatic campaign, engaging U.S. intelligence and national-security interlocutors to secure Washington’s continued allowance for operations on Diego Garcia.
British negotiators reportedly involved the prime minister’s national security adviser, Foreign Office and Downing Street teams, as well as contacts across the White House, State Department and U.S. intelligence community. The talks concluded after a telephone call between Mr. Starmer and Mr. Trump in which safeguards for the base’s operation were discussed; British defence secretary John Healey is also believed to have been in touch with his U.S. counterpart, Hegseth.
The outcome matters beyond a bilateral spat. Diego Garcia is a lynchpin of U.S. power projection in the Indian Ocean and a strategic asset in any competition with China; its operational continuity is therefore a priority for both London and Washington. The resolution also has legal and moral dimensions: Mauritius has signalled it might litigate before international courts, and displaced Chagossians continue to seek restitution and the right to return. How the treaty’s implementation balances sovereignty, basing rights and the claims of the islanders will test the durability of allied arrangements in a volatile strategic theatre.