U.S. President Donald Trump said on Tuesday that Britain’s plan to cede sovereignty of the island of Diego Garcia in the Chagos Islands to Mauritius was an “act of total weakness,” adding that it was “another in a very long line of national security reasons why Greenland has to be acquired”.

The island of Diego Garcia houses a strategically important U.S.-UK air base in the Indian Ocean.

Britain and Mauritius last year struck a deal to pass on the sovereignty of the Chagos islands to Mauritius while allowing Britain to retain control of the air base under a long-term lease.

Trump wrote on his Truth Social account: “Shockingly, our ‘brilliant’ NATO Ally, the United Kingdom, is currently planning to give away the Island of Diego Garcia, the site of a vital U.S. Military Base, to Mauritius, and to do so FOR NO REASON WHATSOEVER.”

Trump said there was no doubt that “China and Russia have noticed this act” by Britain.

The UK government did not immediately respond to a Reuters’ request for comment on Tuesday.

UK – Mauritius deal

ISLANDERS DISPLACED

The Chagos Archipelago is a group of six atolls with more than 600 islands in the Indian Ocean, 500 km (300 miles) south of the Maldives and halfway between Africa and Indonesia.

Around 4,000 people are currently stationed on the islands.

No indigenous inhabitants, often referred to as Chagossians or Ilois, have lived there since Britain forcibly displaced up to 2,000 people, mostly former agricultural workers, from the islands in the late 1960s and early 1970s to establish the Diego Garcia base.

THE DEAL

Under increasing international pressure, Britain agreed in October 2024 to transfer sovereignty of the Chagos Islands to Mauritius, a former colony that gained independence in 1968. The deal, however, drew criticism from lawmakers as well as Britons born on Diego Garcia.

In May 2025, Britain said it would pay Mauritius 101 million pounds ($136 million) per year – calculated to be worth 3.4 billion pounds over the lifetime of the deal – to secure the future of the Diego Garcia military base under a 99-year lease.

At the time, the U.S. said it “welcomed the historic agreement”, commending both countries’ leaders for their vision. In February 2025, ahead of the signing, Trump also expressed preliminary support for the deal.

Canada, Australia, New Zealand and India have also backed the agreement.

SIGNIFICANCE

Diego Garcia serves as a key military base in the Indian Ocean for the U.S. and Britain.

Recent operations launched from Diego Garcia include bombing strikes against Houthi targets in Yemen in 2024 and 2025, humanitarian aid deployments to Gaza and attacks against Taliban and al Qaeda targets in Afghanistan in 2001.

China also has a growing reach in the region, including close trade ties with Mauritius.

UN COURT’S VIEW

Britain split the archipelago off from its colonial island territory of Mauritius in 1965, three years before granting independence to Mauritius – minus the islands.

In 2019 after a request by the United Nations General Assembly, the International Court of Justice issued a non-binding ruling calling on Britain to give up control, saying it wrongfully forced the population to leave to make way for the base.

CONCERNS

U.S. Secretary of State Marco Rubio raised concerns in February 2025 about potential threats to U.S. security, particularly in light of China’s influence in the region.

Mauritian Prime Minister Navin Ramgoolam, who was elected after the initial agreement was reached, also questioned the deal when he took office. Ramgoolam had wanted Trump to look at the plan and say whether it was a good arrangement.

Some Chagossians, many of whom ended up living in Britain after being removed from the archipelago, have protested against the agreement on the grounds that they were not consulted.

Kemi Badenoch, leader of the opposition in Britain, said on Tuesday on X that the deal was “complete self sabotage” that made “us and our NATO allies weaker”.

LEGAL CHALLENGE

Before the deal was signed, a UK High Court judge issued a last-minute injunction sought by Bernadette Dugasse and Bertrice Pompe, British nationals who were born in Diego Garcia and criticised the deal for excluding Chagossians.

The injunction was overturned hours later by Britain’s High Court, clearing the way for the deal to be signed.

Trump has previously said that the encroaching presence of China and Russia makes Greenland vital to U.S. security interests, and repeatedly insisted he will settle for nothing less than ownership of Greenland.

Britain’s deal with Mauritius was delayed after the Trump’s inauguratiPresident Donald Trump said on Tuesday that Britain’s deal to cede sovereignty of the island of Diego Garcia in the Chagos Islands to Mauritius was an “act of total weakness,” adding that it was “another in a very long line of national security reasons why Greenland has to be acquired”.

The island of Diego Garcia houses a strategically important U.S.-UK air base in the Indian Ocean.

Britain and Mauritius last year struck a deal to pass on the sovereignty of the Chagos islands to Mauritius while allowing Britain to retain control of the air base under a long-term lease.

The deal had previously been supported by the U.S. administration which said when it was signed in May that it “welcomed” the agreement and commended efforts to secure the long-term operation of the joint military base.

UK MINISTER SAYS DEAL IS BEST OPTION

Trump wrote on his Truth Social account: “Shockingly, our ‘brilliant’ NATO Ally, the United Kingdom, is currently planning to give away the Island of Diego Garcia, the site of a vital U.S. Military Base, to Mauritius, and to do so FOR NO REASON WHATSOEVER.”

Trump said there was no doubt that “China and Russia have noticed this act” by Britain.

British senior minister Darren Jones said on Tuesday that the deal was the best option for the military base, allowing it to operate for the next 100 years.

“The treaty has already been signed,” Jones told Times Radio, adding that that could not now be changed.

“The best way we believe for Britain to respond … is convening around the world using our diplomatic heft and using the Prime Minister’s relationship with the President to protect British interests,” he added.

Britain’s Prime Minister Keir Starmer has built a solid relationship with Trump, becoming the first leader to secure a deal to lower some tariffs, but their connection has been shaken in recent days with disagreement over Trump’s approach to Greenland and now his comments on Diego Garcia.

Trump has previously said that the encroaching presence of China and Russia makes Greenland vital to U.S. security interests, and repeatedly insisted he will settle for nothing less than ownership of Greenland.

Britain’s deal with Mauritius was delayed after Trump’s inauguration in January 2025, with London wanting to give the new administration time to examine the details of the plan.on in January 2025, with London wanting to give the new administration time to examine the details of the plan.

In February of that year, Trump indicated he was “inclined to go along” with Britain on the agreement.