LONDON   -   The UK has announced it is giving up sovereignty of a remote but strategically important cluster of islands in the Indian Ocean after more than half a century. The deal – reached after years of negotiations - will see the UK hand over the Chagos Islands to Mauritius in a historic move.

This includes the tropical atoll of Diego Garcia, used by the US government as a military base for its navy ships and long-range bomber aircraft.

The announcement, made in a joint statement by the UK and Mauritian Prime Ministers, ends decades of often fractious negotiations between the two countries. The US-UK base will remain on Diego Garcia – a key factor enabling the deal to go forward at a time of growing geopolitical rivalries in the region between Western countries, India, and China. The BBC visits the secretive Chagos Islands military base The deal is still subject to finalisation of a treaty, but both sides have promised to complete it as quickly as possible.

“This is a seminal moment in our relationship and a demonstration of our enduring commitment to the peaceful resolution of disputes and the rule of law,” the statement from UK Prime Minister Keir Starmer and Mauritius Prime Minister Pravind Jugnauth read. The leaders also said they were committed “to ensure the long-term, secure and effective operation of the existing base on Diego Garcia which plays a vital role in regional and global security”. The treaty will also “address wrongs of the past and demonstrate the commitment of both parties to support the welfare of Chagossians”. The UK will provide a package of financial support to Mauritius, including annual payments and infrastructure investment. Mauritius will also be able to begin a programme of resettlement on the Chagos Islands, but not on Diego Garcia.

There, the UK will ensure operation of the military base for “an initial period” of 99 years.

US President Joe Biden welcomed the “historic agreement”, saying it was a “clear demonstration that through diplomacy and partnership, countries can overcome long-standing historical challenges to reach peaceful and mutually beneficial outcomes”.

He said it secured the future of a key military base which “plays a vital role in national, regional, and global security.”

Amongst the Chagossians, opinions are divided. Isabelle Charlot, speaking on BBC Radio 4’s World At One programme, said the deal brought back hopes her family could return to her father’s island “roots”.

Plans for the Mauritius government to arrange resettlement would mean a “place that we can call home - where we will be free,” she said.

But Frankie Bontemps, a second generation Chagossian in the UK, told the BBC that he felt “betrayed” and “angry” at the news because “Chagossians have never been involved” in the negotiations.

“We remain powerless and voiceless in determining our own future and the future of our homeland”, he said, and called for the full inclusion of Chagossians in drafting the treaty.