The UK and Mauritius are seeking a breakthrough over the Chagos Islands agreement as leaders gather in New York for the United Nations General Assembly.
The agreement would transfer sovereignty over the Chagos Archipelago to Mauritius. However, the UK would retain control of the military base on Diego Garcia under a 99-year arrangement.
The deal has not yet taken effect.
US President Donald Trump has raised concerns about the agreement. He previously called it a “big mistake” and questioned its impact on the security of the Diego Garcia base.
UK and Mauritius hold new talks
British Prime Minister Andy Burnham spoke with Mauritian Prime Minister Navin Ramgoolam before travelling to New York.
The two leaders discussed the future of Diego Garcia.
Burnham said the UK remained committed to finding a way forward with Mauritius and the United States.
The two leaders also agreed that their foreign ministers should meet during the UN General Assembly.
According to the UK government, the talks will focus on strengthening relations between Britain and Mauritius.
Why Diego Garcia matters
Diego Garcia hosts a major joint UK-US military base in the Indian Ocean.
The base has supported British and American military operations for decades.
As a result, its future has become a central part of negotiations over the Chagos Islands.
Under the agreement signed in 2025, Mauritius would gain sovereignty over the Chagos Archipelago.
At the same time, Britain would retain the rights needed to operate the Diego Garcia base for an initial 99 years.
The UK says this arrangement is designed to protect the long-term operation of the base.
Chagos Islands agreement remains on hold
However, the agreement still needs legal changes in Britain before it can take effect.
Trump’s concerns have added another challenge to the process.
The US president has questioned whether transferring sovereignty could affect American security interests.
Burnham said Britain would continue working with both Mauritius and the United States to address the concerns.
Under the agreement, Britain would pay Mauritius an average of about £101 million per year during the initial 99-year period.
The UK government estimates the net present value of those payments at about £3.4 billion, or roughly $4.5 billion.
That figure does not represent an upfront payment.
Long-running sovereignty dispute
The Chagos dispute dates back decades.
Britain separated the Chagos Islands from Mauritius before Mauritius gained independence in 1968.
Chagossians were later removed from the islands as the military base on Diego Garcia was developed.
In 2025, Britain and Mauritius signed an agreement under which Mauritius would become sovereign over the archipelago once the treaty enters into force.
For now, however, implementation remains pending.
The UN General Assembly meetings in New York provide another opportunity for British and Mauritian officials to discuss a possible way forward.