UK hands Indian Ocean islands to Mauritius but keeps key US military base

The deal comes after nearly two years of negotiations and marks a significant turnaround after decades of British dismissals of Mauritian sovereignty claims.
At the start of the talks in 2023, the two sides agreed that the Diego Garcia military base would continue to operate regardless of the outcome.
In 2016, the UK extended the US lease of the military base until 2036.
The joint statement said that Britain and Mauritius would work on a treaty finalising the accord that would ensure Diego Garcia’s operation “well into the next century”.
The treaty could also pave the way for the return of Chagos islanders, who were expelled by the UK in the 1970s as the military base was developed.
But with no permanent population – and with Diego Garcia possibly the only habitable island but remaining off-limits as part of the deal – resettlement looks unlikely.
Mauritius has claimed the archipelago – renamed the British Indian Ocean Territory – since its independence in 1968 and has garnered increased international support.
In 2019 the International Court of Justice advised Britain to hand over the remote islands. During the hearings, the UK apologised for the “shameful” eviction of islanders but ignored the ICJ ruling at the time.
The same year, the UN General Assembly also passed a resolution calling on Britain to “withdraw its colonial administration”.
Without the agreement, “the long-term, secure operation” of the military base would be under threat, including through legal challenges posed by international courts, Britain’s foreign ministry said.
“Today’s agreement secures this vital military base for the future,” Foreign Secretary David Lammy said, adding that the deal would also shut down the potential for the islands to be used as a “dangerous illegal migration route to the UK”.
In addition, the UK announced a “package of financial support” to Mauritius including an annual payment and an infrastructure partnership.
The statement claimed that the agreement resolves “all outstanding issues between the United Kingdom and Mauritius”.
It said the two countries would also cooperate on environmental and irregular migration.