Chagos Sovereignty Deal Faces Further Delays as UK-Mauritius Talks Stall

Author: Mauritius Ranking
Author Bio: Mauritius Ranking covers Mauritius current affairs, international relations, politics, diplomacy, law and major national developments.

Published Date: 2 October 2026
Updated Date: 3 October 2026

The proposed agreement on the Chagos Archipelago is facing further uncertainty as efforts to move the UK-Mauritius sovereignty deal forward remain unresolved.

The issue returned to the diplomatic agenda in September, with Mauritius and the United Kingdom holding discussions about the future of the archipelago and the strategically important Diego Garcia military base. However, the agreement has yet to enter into force, while the United States’ position remains a major factor in the negotiations.

For Chagossians who have waited decades for the possibility of returning to their homeland, the continuing delays have added another layer of uncertainty.

UK-Mauritius Agreement Remains Unimplemented

The UK and Mauritius signed a treaty concerning the Chagos Archipelago on 22 May 2025.

Under the agreement, Mauritius would exercise sovereignty over the archipelago, while arrangements would allow the United Kingdom to continue exercising rights over the Diego Garcia military base for an initial period of 99 years.

The agreement also provides for Mauritius to arrange the resettlement of Chagossians on islands other than Diego Garcia. However, the treaty has not yet entered into force.

The implementation process has faced political and legislative obstacles since the agreement was reached.

US Position Continues to Affect the Deal

One of the central issues is the future of Diego Garcia, which hosts a joint UK-US military facility.

In September, UK Defence Secretary Wes Streeting said the agreement could not proceed without US support. He also said payments to Mauritius linked to the proposed arrangement were on hold at that stage.

The Guardian also reported that UK officials believed the agreement remained on hold while US President Donald Trump’s opposition continued, although Prime Minister Andy Burnham said he was confident that a way forward could be found.

The situation means that the future of the sovereignty agreement is connected not only to discussions between Mauritius and Britain but also to Washington’s position on the military base.

Renewed Talks Take Place in September

The issue received renewed diplomatic attention after British Prime Minister Andy Burnham spoke with Mauritian Prime Minister Navin Ramgoolam on 21 September.

According to the UK government, Burnham said Britain wanted to work with Mauritius and the United States on a way forward that would secure the operation of Diego Garcia and protect UK national security.

The two leaders agreed to remain in close contact, while their foreign ministers were expected to continue discussions during the United Nations General Assembly in New York.

Ramgoolam subsequently travelled to the United Kingdom for further discussions with British officials, including National Security Adviser Jonathan Powell.

Mauritius has provided limited public information about the substance of those discussions.

Mauritius Maintains Its Position on Sovereignty

Mauritius has continued to maintain that sovereignty over the Chagos Archipelago is a central issue in the dispute.

During the United Nations General Assembly in September, Foreign Minister Dhananjay Ramful reiterated Mauritius’ position on sovereignty and referred to the 2025 agreement as an important development in the long-running dispute.

The Mauritian government has also continued to emphasise diplomacy and dialogue in addressing the outstanding issues.

The precise terms of any possible changes to the existing agreement, however, remain unclear as talks continue.

Why Diego Garcia Is Central to the Dispute

Diego Garcia is the largest island in the Chagos Archipelago and hosts the strategically important military base operated jointly by the United States and United Kingdom.

The military facility is the most sensitive component of the sovereignty negotiations.

The 2025 treaty was designed to allow Mauritius to exercise sovereignty while providing the UK with continued rights connected to the operation of the base for 99 years.

The United Kingdom has repeatedly described maintaining the base as an important national-security objective. Its original agreement with Mauritius was presented as a way to secure the long-term operation of the facility.

The US position has subsequently complicated the implementation of that arrangement.

Chagossians Remain Concerned About Further Delays

The continuing uncertainty has particular significance for Chagossians who were removed from the islands decades ago.

Britain separated the Chagos Archipelago from Mauritius in 1965, three years before Mauritius became independent. Between 1968 and 1973, an estimated 1,400 to 1,700 Chagossians were removed from the islands and subsequently resettled mainly in Mauritius and Seychelles, with others later moving to the United Kingdom.

The proposed 2025 agreement included provisions allowing resettlement on islands other than Diego Garcia.

For older members of the Chagossian community, however, every additional delay carries a personal significance because many of those displaced from the archipelago are now elderly.

The Chagos Refugees Group has expressed concern that some members may not live long enough to see the agreement’s provisions implemented.

International Legal Background

The sovereignty dispute has also been considered by international legal institutions.

The International Court of Justice (ICJ) issued an advisory opinion in 2019 concerning the legal consequences of the UK’s administration of the Chagos Archipelago.

The International Tribunal for the Law of the Sea subsequently addressed related issues in 2021.

The 2025 UK-Mauritius treaty followed years of diplomatic negotiations over the territory’s future.

These legal developments form part of the wider background to the current negotiations, although the practical implementation of the 2025 agreement remains a political and diplomatic matter.

UK Parliament Faces Further Delay

Another obstacle concerns the legislation required in the United Kingdom to implement the agreement.

The UK government told Parliament in April that the legislation could not complete its passage during the 2024–26 parliamentary session. That session ended on 29 April without the bill completing the required process.

The lack of completed legislation has contributed to the agreement remaining unimplemented.

Further parliamentary action would therefore be required if the treaty is ultimately revived and brought into force.

The Future of the Agreement Remains Unclear

At present, there is no confirmed date for the treaty to enter into force.

The latest discussions indicate that Britain, Mauritius and the United States remain engaged with the question of Diego Garcia, but the precise terms of any revised arrangement have not been publicly settled.

Reports have suggested that finding a formula acceptable to Washington remains a significant challenge. At the same time, Mauritius continues to maintain its position on sovereignty over the Chagos Archipelago.

This leaves the 2025 agreement in a state of uncertainty while diplomatic discussions continue.

A Long-Running Dispute Enters Another Phase

The Chagos issue has been unresolved for decades, involving questions of sovereignty, the rights of displaced Chagossians, international law and strategic military interests.

The latest developments show that reaching an agreement between two governments does not necessarily guarantee immediate implementation.

The future of Diego Garcia, the position of the United States, UK parliamentary approval and the rights and interests of Chagossians all remain important elements of the discussion.

Final Thought

The UK-Mauritius Chagos sovereignty agreement remains stalled more than a year after the treaty was signed. Renewed diplomatic discussions in September have kept the issue active, but the lack of US support and the unresolved future of Diego Garcia continue to complicate implementation.

For Mauritius, the negotiations concern sovereignty over the Chagos Archipelago. For Chagossians, they also concern the possibility of returning to their ancestral islands. As talks continue, the timing and final terms of any agreement remain uncertain.