UK Reviews Chagos Islands Deal After Trump Calls It 'Terrible'

The UK government is reassessing its agreement to transfer sovereignty of the Chagos Islands to Mauritius following US President Donald Trump's renewed criticism of the deal at the UN General Assembly on September 23, 2026. During a face-to-face meeting with UK Prime Minister Andy Burnham in New York, Trump called the deal "terrible" and said the UK would be "looking" at it. Defence Secretary Wes Streeting confirmed the review on the BBC, stating that the deal cannot proceed without American support and that "we have to do more work with our American allies" to reach a position Trump can support.

The Chagos Islands are a remote Indian Ocean archipelago that have been under British control since 1814. In 1965, the UK separated the islands from Mauritius—three years before Mauritius gained independence—to establish the British Indian Ocean Territory and build the Diego Garcia military base. The US has described Diego Garcia as "an all but indispensable platform" for security operations in the Middle East, South Asia, and East Africa, hosting approximately 2,500 mostly American personnel. The base has supported US military operations spanning from Vietnam to Iraq and Afghanistan, and was the target of Iranian missile attacks in March 2026.

Under the May 2025 agreement that was paused in April 2026 when Trump withdrew support, the UK would cede sovereignty to Mauritius while leasing back the Diego Garcia base for 99 years at an annual cost of £101 million ($136 million). The UK government estimates a net overall cost of £3.4 billion, though critics claim the figure could reach £35 billion when adjusted for inflation. Streeting acknowledged that UK governments under Boris Johnson, Keir Starmer, and Andy Burnham had recognised that an ongoing Mauritian legal challenge to the 1965 separation—supported by UN and International Court of Justice opinions—posed a security risk to the base. Burnham told broadcasters that securing the base's future "is critical" for both UK and US security interests and pledged to work hard to find a resolution.

Opposition voices in the UK have raised concerns about the arrangement. Conservative leader Kemi Badenoch called for the deal to be scrapped entirely. Reform UK leader Nigel Farage declared "the Chagos deal is dead." Some right-wing figures, including shadow defence secretary James Cartledge, argued that transferring British sovereign territory risked allowing China strategic access to the region. The Chinese ambassador to Mauritius expressed support for Mauritius's position on the islands. Streeting rejected suggestions that the UK strategy was to wait out Trump's presidency, calling cooperation with the Trump administration "difficult and require significant effort."

The deal still requires parliamentary ratification and the review does not constitute a formal process with a specific timeframe. Both Burnham and Streeting indicated their intention to work toward a solution acceptable to all parties, including the Trump administration, with the aim of ensuring long-term security for Diego Garcia.