MAURITIUS · CHAGOS ISLANDS
Key Facts
- The country Mauritius is an Indian Ocean island nation claiming the Chagos Islands, which host Diego Garcia’s military base.
- The background A treaty signed on 22 May 2025 recognises Mauritian sovereignty and lasts 99 years once in force.
- What happened UK Prime Minister Andy Burnham met Mauritius’s Navin Ramgoolam in Antigua on Wednesday 4 November 2026.
- The catch They agreed only to work on a shared plan by the end of 2026.
- What it means for you Diego Garcia hosts a joint UK-US base, so any legal change touches US security.
- What comes next A shared plan is due by the end of 2026; Mauritius has warned it may go to court.
UK Prime Minister Andy Burnham and Mauritius’s prime minister, Navin Ramgoolam, agreed on Wednesday 4 November 2026 to work on a shared plan to move the Chagos Islands deal forward by the end of the year. The UK government said they met during the retreat at the Commonwealth Heads of Government Meeting in Antigua, a biennial summit of the 56-nation Commonwealth, a group of mostly former British territories.
The Chagos Islands are an archipelago in the Indian Ocean that Mauritius claims and that the United Kingdom has governed; its largest island, Diego Garcia, hosts a military base run jointly by the UK and the United States. A treaty signed in 2025 would recognise Mauritian sovereignty, but the UK Parliament’s record shows no ratification, so the new plan matters.
What the UK Says Was Agreed
In its readout, published on Thursday 5 November, the UK government said Burnham underlined his commitment to working with Mauritius and the United States on a way forward that secures the operation of the Diego Garcia base and protects the national security of all three countries. It added that the two leaders agreed to work on a shared plan to make further progress by the end of the year.
The readout gives no ratification date and no list of steps for the plan.
Where the Treaty Stands
The agreement between the United Kingdom and Mauritius was signed in London and Port Louis on 22 May 2025. Its text says Mauritius is sovereign over the Chagos Archipelago, including Diego Garcia, and that the agreement lasts 99 years from entry into force.
The treaty defines the base as the jointly operated UK-US military facilities, installations and activities on Diego Garcia, and it enters into force only after both sides notify each other that their internal procedures are complete. The UK Parliament’s treaty record shows scrutiny concluded on 3 July 2025 and lists ministerial statements on 13 and 14 April 2026 about a bill to implement the treaty, with no ratification recorded.
Mauritian press reports of 9 October said Ramgoolam told Jonathan Powell, the UK national security adviser, in London on 2 October that the lack of ratification made the status quo untenable. The same reports said he warned that legal action would become inevitable if the matter were not settled quickly.
The New British Prime Minister
Andy Burnham became UK Prime Minister on 20 July 2026, according to the British government. The Antigua meeting put Ramgoolam face to face with the new leader on the Chagos question.
What Comes Next
The UK readout sets the end of 2026 as the horizon for the shared plan and names no further meeting. The UK Parliament’s treaty record, which runs to 14 April 2026, lists the implementing-bill statements as the latest UK step logged.
What It Means for US Readers
The Diego Garcia base is jointly operated by the UK and the US, so any change to its legal basis is a US security matter as well as a British and Mauritian one. Burnham’s stated commitment to work with Mauritius and the United States shows that Washington is part of the discussion.
If the plan stalls, Mauritius has warned that it may go to court, which could add legal uncertainty around a base used by US forces. The year-end horizon is the next marker to watch.
What Is Not Known
- What the shared plan will contain and whether the United States will back it. The UK Foreign Office and the Mauritian government can answer; the readout points to the end of 2026.
- When the UK will ratify the treaty. The UK government can answer, and the Parliament record shows only the April 2026 statements on the implementing bill.
Frequently Asked Questions
What are the Chagos Islands?
They are an archipelago in the Indian Ocean that the United Kingdom has governed and Mauritius claims. One island, Diego Garcia, hosts a military base run jointly by the UK and the US.
What does the 2025 treaty say?
It states that Mauritius is sovereign over the archipelago, including Diego Garcia, and it lasts 99 years from entry into force. It defines the base as the jointly operated UK-US facilities on Diego Garcia.
Has the treaty been ratified?
The UK Parliament’s treaty record shows the treaty signed on 22 May 2025 and ministerial statements in April 2026 on an implementing bill, but no ratification. Mauritian press reports said in October that it remained unratified.
Who is Andy Burnham?
He is the Prime Minister of the United Kingdom and has held the post since 20 July 2026. He met Ramgoolam in Antigua on 4 November.
What is the Commonwealth summit?
It is a meeting of the leaders of the Commonwealth’s 56 member countries, held every two years. This year’s took place in St John’s, Antigua and Barbuda, in early November.
- UK Government, PM meetings with world leaders at CHOGM, 5 November 2026: gov.uk
- UK Government and Mauritius, Agreement concerning the Chagos Archipelago including Diego Garcia, CP 1334, 22 May 2025: gov.uk
- UK Parliament, treaty record for the Chagos agreement: parliament.uk
- UK Government, Prime Minister page: gov.uk
- Commonwealth Secretariat, CHOGM 2026: thecommonwealth.org
This article was produced by The Rio Times’ automated newsroom system. How we use AI · Report an error · Editorial responsibility: Matthias Camenzind, Editor-in-Chief