Trump says U.K. return of Chagos Islands to Mauritius is a reason to acquire Greenland

LONDON — President Trump has accused the U.K. of “great stupidity” over its decision last year to give up sovereignty of the Chagos Islands, an archipelago in the Indian Ocean and home to one of the most important U.S.-U.K. military bases at Diego Garcia.

Trump suggested that Britain’s decision to cede the islands to Mauritius is one of the reasons behind his desire to take over the semi-autonomous territory of Greenland, which is controlled by Denmark.

Under the Chagos agreement — signed by the U.K. and Mauritius in May 2025 — the U.K. can continue leasing Diego Garcia, keeping the key military facility in British and American hands for 99 years at a cost of more than $100 million a year. U.K. Prime Minister Keir Starmer has described Diego Garcia as vital for Britain’s defense, intelligence and national security.

The U.S. had previously signaled support for the agreement between the U.K. and Mauritius, with Secretary of State Marco Rubio saying in a statement last May that President Trump “expressed his support for this monumental achievement.”

But in a post on Truth Social early Tuesday morning — just hours before a historic address to the U.K. Parliament by House Speaker Mike Johnson — Trump took a markedly different tone. “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 in the post.

“There is no doubt that China and Russia have noticed this act of total weakness,” he said. “The UK giving away extremely important land is an act of GREAT STUPIDITY, and is another in a very long line of National Security reasons why Greenland has to be acquired.”

This change in tone is the latest strain on the transatlantic relationship, and comes a day after Starmer insisted in a national address that “calm discussions between allies” was the best way to overcome differences with the U.S. over Greenland.

In response to Trump’s criticisms, the British prime minister’s office said in a statement on Tuesday that the deal was necessary to protect the U.S.-U.K. military base.

“The UK will never compromise on our national security. We acted because the base on Diego Garcia was under threat after court decisions undermined our position and would have prevented it operating as intended in future,” the statement said, referring to past international court rulings that sided with Mauritius and said the U.K. had to give up sovereignty of the Chagos Islands. “This deal secures the operations of the joint US-UK base on Diego Garcia for generations, with robust provisions for keeping its unique capabilities intact and our adversaries out.”

The statement said that the agreement had been backed by the U.K.’s intelligence allies, including the U.S., saying, “it has been publicly welcomed by the US, Australia and all other Five Eyes allies, as well as key international partners including India, Japan and South Korea.”

Speaking in the House of Commons, Minister of State for Europe, North America and Overseas Territories Stephen Doughty said he was “surprised” by Trump’s comments, and said the U.K. would “have discussions with the [U.S.] administration in the coming days to remind them of the strength of this deal and how it secures the base.”

House Speaker Johnson, in the U.K. to mark 250 years of U.S. independence, acknowledged mounting tensions in his remarks to the Parliament, saying he’d spoken with the president on Monday and “I felt that my mission here today was to encourage our friends and help to calm the waters, so to speak.”

He said the two countries would continue to work through their differences as friends.