The UK government has decided to revise its agreement to hand sovereignty of the Chagos Islands to Mauritius, after strong opposition from US President Donald Trump. The decision followed the first meeting between Trump and new British Prime Minister Andy Burnham on the sidelines of the UN General Assembly.

UK Defence Secretary Wes Streeting said the deal cannot go ahead in its current form without US support. As a result, the annual £101 million ($136 million) payment to Mauritius has been put on hold. The payment was set out in the agreement signed in 2025 under former Prime Minister Keir Starmer, and totals more than £3.4 billion over 99 years.

Under the deal, Mauritius would gain sovereignty over the archipelago, while the joint UK-US military base on Diego Garcia, the largest island, would remain under a 99-year lease to Britain. Trump, along with the UK’s Conservative and Reform UK parties, has opposed the arrangement. They argue that Mauritius’s close ties with China could expose the key US base to outside influence. Burnham said his government is working with US officials to amend parts of the agreement so that long-term defence and security interests are protected.

In a 2019 advisory opinion, the International Court of Justice found that Britain’s separation of Chagos from Mauritius in 1965, before Mauritian independence, breached the principles of decolonisation. The court said the islands should be returned to Mauritius as soon as possible. The UN General Assembly has since passed several resolutions calling for the ruling to be implemented.