NEW YORK, United States – U.S. President Donald Trump praised Britain’s new prime minister, Andy Burnham, after their first face-to-face meeting at the United Nations on Tuesday, while sharply criticizing the UK’s agreement to transfer sovereignty over the Chagos Archipelago to Mauritius.
The meeting brought a notably warm tone to the first encounter between the two leaders, but it also exposed a significant strategic disagreement over Diego Garcia, the Indian Ocean island that hosts a major joint U.S.-UK military facility.
Trump said U.S.-UK relations were doing well under Burnham and described the British prime minister as a “natural business person.” Burnham, who became prime minister in July, said the two had established a good connection during earlier conversations and had developed it further during their meeting.
The leaders discussed trade, migration, Ukraine, the Falkland Islands, the war involving Iran and the future of Diego Garcia, according to the British government.
The Chagos dispute remained unresolved after the meeting.
Trump objects to the Chagos agreement
Trump said he did not support the UK-Mauritius agreement, calling it a “terrible” deal and emphasizing the strategic importance of Diego Garcia.
He also linked the base to U.S. military operations, saying American B-2 bombers had needed to fly from Missouri during strikes on Iranian nuclear facilities rather than operating from the Indian Ocean location. Trump said Burnham would be looking at the agreement, and Burnham agreed that he would.
Trump’s comments represent opposition to the existing agreement rather than evidence that Britain has abandoned it.
The British government said after the meeting that Burnham remained committed to working with all parties to find a solution concerning Diego Garcia.
What the UK-Mauritius agreement provides
Britain and Mauritius signed the agreement concerning the Chagos Archipelago on May 22, 2025.
Under the treaty, the UK recognizes Mauritian sovereignty over the Chagos Archipelago while retaining rights connected to the operation of the Diego Garcia military base. The agreement provides for a long-term arrangement covering the base.
The treaty was intended to resolve the sovereignty dispute while preserving the military facility’s continued operation.
The House of Commons Library says the agreement would allow Mauritius to exercise sovereignty over the archipelago while the UK retains rights on Diego Garcia.
The arrangement has not, however, completed the domestic process necessary for implementation.
Implementation remains unresolved
The UK government has not said that it is abandoning the 2025 treaty.
Instead, Burnham has been seeking a way forward involving Mauritius and the United States.
On Monday, before his meeting with Trump, Burnham spoke with Mauritian Prime Minister Navin Ramgoolam. Downing Street said Burnham reaffirmed his commitment to working with Mauritius and the United States on an arrangement that would secure the continued operation of Diego Garcia and protect UK national security.
Mauritius has likewise continued to describe the 2025 agreement as the basis for resolving the issue.
A Mauritian government document says the agreement recognizes Mauritian sovereignty over the entire Chagos Archipelago, including Diego Garcia, while noting that UK ratification procedures remain outstanding.
The result is a three-way diplomatic problem.
Britain wants to preserve the military facility and its strategic role.
Mauritius wants the sovereignty arrangement recognized and implemented.
The United States is pressing for arrangements that it considers sufficient to protect the military value of Diego Garcia.
Why Diego Garcia matters
Diego Garcia is located in the central Indian Ocean, far from the territory of both Britain and the United States but within reach of major areas of strategic importance.
The military facility has supported U.S. and UK operations across the wider Indian Ocean and Middle East.
Its location provides a long-range operating base for aircraft and a logistics position that cannot easily be replicated elsewhere.
That strategic value is central to Trump’s opposition.
His comments focused not on the wider sovereignty question alone but on what he described as the military importance of the island and the consequences of losing direct access to the existing arrangement.
The British government has also repeatedly emphasized the importance of securing the base’s long-term operation.
Before his meeting with Trump, Burnham said the government remained determined to secure the base’s future. Downing Street subsequently said he had discussed Diego Garcia with Trump and reaffirmed his commitment to finding a solution.
A disagreement inside an otherwise close relationship
The Chagos issue illustrates the difference between a close alliance and complete agreement on strategic policy.
Trump publicly praised Burnham and described the relationship positively.
The British government said the leaders emphasized the closeness of the bilateral relationship and the importance of trade. They also discussed Ukraine, Iran, migration and the Falkland Islands.
At the same time, Trump made clear that he opposed one of Britain’s major foreign-policy agreements.
Burnham did not announce a reversal.
Instead, the British government’s post-meeting statement used the language of finding a solution with all parties.
That leaves the central question open: whether Britain, Mauritius and the United States can modify the arrangements surrounding Diego Garcia without undermining the 2025 sovereignty agreement.
The Mauritius position remains part of the equation
Mauritius has maintained that the Chagos Archipelago forms part of its territory and has continued to support the 2025 agreement.
Its government says the treaty recognizes Mauritian sovereignty over the archipelago and describes the remaining UK ratification process as necessary to complete the arrangement.
The issue therefore cannot be resolved solely through a Washington-London understanding.
Any change to the existing framework would also involve Mauritius, which is the other party to the 2025 treaty.
That makes Burnham’s statement that Britain is working with “all parties” significant: the UK is attempting to address U.S. concerns while maintaining a relationship with Mauritius over the treaty it already signed.
What happens next
The immediate diplomatic task is to determine whether the three governments can agree on arrangements that preserve Diego Garcia’s military function while addressing the unresolved implementation of the Chagos agreement.
No such new agreement was announced at the Trump-Burnham meeting.
The UK government said the leaders looked forward to speaking again, while Burnham has separately indicated that Britain wants to continue discussions with Mauritius and the United States.
For now, the positions are clear but the outcome is not.
Trump has rejected the existing arrangement.
Burnham has said he will work with the parties toward a solution.
Mauritius continues to support the treaty recognizing its sovereignty over the Chagos Archipelago.
The 2025 agreement remains the formal basis of the proposed settlement, but its implementation remains unresolved.
The meeting therefore produced a warmer U.S.-UK relationship at the leadership level without resolving one of the most sensitive strategic disagreements between Washington and London.
Reporting Credit: United Kingdom Prime Minister’s Office — September 22 Trump-Burnham meeting and UK position on Diego Garcia; UK Foreign, Commonwealth & Development Office — 2025 UK-Mauritius Chagos agreement; UK Parliament/House of Commons Library — treaty provisions and implementation status; Government of Mauritius — position on Chagos sovereignty and treaty implementation; White House — President Trump’s September 22 UN statements and U.S. foreign-policy position.
