INDIAN OCEAN — Under the terms of the stalled accord, the U.K. government agreed to pay Mauritius at least 120 million pounds ($159 million) annually to lease back Diego Garcia for at least 99 years. The financial structure specified that Mauritius was set to receive 165 million pounds for the first three years and 120 million pounds annually from the fourth year onward. The agreement includes a provision that the military base at Diego Garcia would remain under British control for at least 99 years, with the possibility of renewal for an additional 40 years and further periods thereafter. Diego Garcia is home to approximately 2,500 mostly American personnel.

The United States has described Diego Garcia as "an all but indispensable platform" for security operations in the Middle East, South Asia, and East Africa. The base saw active use last year when the U.S. deployed nuclear-capable B-2 Spirit bombers there during airstrike campaigns targeting Houthi rebels in Yemen. In March 2026, Iran launched missiles in an unsuccessful attempt to hit the Diego Garcia base. Streeting stated that ignoring Mauritius’s claim to sovereignty posed a risk to the future of the Diego Garcia military base.

Legislation to ratify the Chagos Islands agreement ran out of time before the U.K. Parliament's session ended in May 2026. Burnham stated that he was confident the U.K. could work out an agreement with the U.S. regarding the Chagos Islands. Streeting stated that resolving the Chagos Islands dispute will involve "painstaking work."

Timeline

In January 2025, the U.S. deployed nuclear-capable B-2 Spirit bombers to Diego Garcia during airstrike campaigns targeting Houthi rebels in Yemen. By May 2025, the sovereignty agreement was signed after receiving backing from the Trump administration, and the U.K. government agreed to pay Mauritius at least 120 million pounds ($159 million) annually to lease back Diego Garcia for at least 99 years. Under the agreement, Mauritius was set to receive 165 million pounds for the first three years and 120 million pounds annually from the fourth year onward.

In January 2026, Donald Trump posted on social media that the transfer of the Chagos Islands to Mauritius was "an act of GREAT STUPIDITY." On September 23, 2026, U.S. President Donald Trump described the U.K.-Mauritius Chagos Islands agreement as a "terrible deal" during a meeting with Prime Minister Andy Burnham in New York.

What's New

Later reporting confirmed that Donald Trump stated, "I don’t support it," regarding the Chagos Islands sovereignty transfer agreement. Additional documentation includes a study titled "Agreement between the United Kingdom and Mauritius Concerning the Chagos Archipelago Including Diego Garcia" published in 2025 in International Legal Materials. U.K. Defense Secretary Wes Streeting stated that annual payments to Mauritius under the Chagos Islands sovereignty deal are on hold.

Further context emerged from research titled "Chagos Islands Sovereignty Dispute: Mauritius-UK Treaty" published in 2026 in Global Encyclopedia of Territorial Rights. Earlier analysis appeared in research titled "UK hands Chagos Islands to Mauritius, marking the end of a longstanding sovereignty dispute" published in 2024. A study titled "Mauritius' policy toward sovereignty over the Chagos Archipelago: a pluralistic approach to international dispute settlement" was published in 2025 in Frontiers in Political Science. Wes Streeting stated that resolving the Chagos Islands dispute will involve "painstaking work," and he stated that ignoring Mauritius’s claim to sovereignty posed a risk to the future of the Diego Garcia military base.

Why It Matters

The stall in the Chagos Islands agreement shows the strategic importance of Diego Garcia, which the United States has described as "an all but indispensable platform" for security operations in the Middle East, South Asia, and East Africa. The base hosts approximately 2,500 mostly American personnel and was recently targeted by Iranian missiles in March 2026, reflecting the security concerns tied to its status.

Mauritius claims the Chagos Archipelago as part of its territory and argues that the British claim violates United Nations resolutions banning the dismemberment of colonial territories before independence. The UN Committee on the Elimination of Racial Discrimination has expressed "deep concern" at the terms of the Chagos Islands sovereignty deal, adding international scrutiny to the bilateral negotiations between the U.K. and Mauritius.