Diego Garcia
A US Air Force B-1B bomber takes off from the Diego Garcia military base on a strike mission against Afghanistan in Diego Garcia on 07 October 07, 2001. Image Credit: AFP

London: Britain on Thursday said it would give up sovereignty of the Chagos Islands to Mauritius but under what US President Joe Biden called a “historic agreement” will keep its strategic joint military base with the United States on Diego Garcia.

Britain has been under pressure for decades to hand over the Indian Ocean islands but has resisted because of the Diego Garcia base, a key installation used to help US operations across the Indian Ocean and Gulf regions.

“For the first time in more than 50 years, the status of the base will be undisputed and legally secure,” the Foreign Commonwealth and Development Office (FCDO) said.

Biden hailed the continuation of the Diego Garcia base on the largest island in the chain and was used during the wars in Afghanistan and Iraq.

“I applaud the historic agreement and conclusion of the negotiations,” Biden said in a White House statement, adding that the site “plays a vital role in national, regional, and global security”.

Britain decided in 1965 to separate the islands from its then colony of Mauritius and set up a military base there, which it leased to the United States.

In doing so, it evicted thousands of Chagos islanders who have since mounted a series of legal claims for compensation in the British courts.

Mauritius has claimed the archipelago - renamed British Indian Ocean Territory - since its independence in 1968. Mauritius Foreign Minister called the announcement of the accord “a day to remember” and a “seminal moment” in his country’s relationship with Britain.

International calls for Britain to hand over one of its last remaining overseas territories have grown in recent years.

In 2019 the International Court of Justice advised Britain to hand over the remote islands. The same year, the UN General Assembly also voted for Britain to withdraw.

Talks on the future of the islands began between the countries in 2022 after years of the UK refusing to relinquish control.

Without the agreement, “the long-term, secure operation” of the military base would be under threat, Britain’s foreign ministry said, including through legal challenges posed by international courts.

“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 use of the islands being used as a “dangerous illegal migration route to the UK”.