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.
Trump has previously said that the growing presence of China and Russia increases Greenland’s importance to U.S. security interests, and has stated that he supports U.S. ownership of the territory.
Britain's deal with Mauritius was delayed after the Trump's inauguration 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.
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