UK Reopens Review of Chagos Islands Deal After Trump Opposition

The UK government is reviewing its agreement to hand sovereignty over the Chagos Islands to Mauritius after US President Donald Trump renewed his opposition to the deal.

Defence Secretary Wes Streeting confirmed the review, saying the United States’ position meant Britain needed to work again with Washington to find an arrangement that could secure long-term support for the agreement.

The original deal would transfer sovereignty of the Chagos Islands to Mauritius while allowing the UK and US to retain access to the military base on Diego Garcia through a 99-year lease. Under the agreement, Britain would pay an average of about £101m ($136m) annually for the lease, with the UK government previously estimating the overall net cost at £3.4bn.

Streeting said the priority was to protect the future of the Diego Garcia base, which he described as one of the UK’s most sensitive and valuable national security assets. He said Britain needed to work with Trump and his administration to make changes that could win American backing.

Trump criticised the agreement during his meeting with Prime Minister Andy Burnham at the UN General Assembly in New York, describing it as a “terrible deal”. Burnham said Britain had inherited the situation and that a resolution was needed to protect the future of the military base while addressing the interests of the different parties.

The agreement was originally signed by Britain and Mauritius in May 2025, but its implementation was paused indefinitely in April after Trump withdrew his support. The final legislation required to transfer sovereignty had also not passed through the UK Parliament.

The dispute is rooted in the history of the Chagos Islands. Mauritius maintains that Britain unlawfully separated the islands from its territory in 1965 as part of the process leading to independence. In 2019, the International Court of Justice issued an advisory opinion saying Britain’s administration of the islands should end as rapidly as possible. The opinion was non-binding but was endorsed by the UN General Assembly.

Streeting said no money would be transferred to Mauritius “at this stage” while officials examine the agreement. The government has not set a specific timetable for the review, while officials have maintained that any final arrangement would require US support.