U.S. President Donald Trump has moved to directly block the British government's plan to return the Chagos Archipelago in the Indian Ocean to Mauritius. Trump says the United States must secure Diego Garcia, a key military outpost, in case nuclear talks with Iran fail. His remarks upend the diplomatic agreement pursued by the British Labor Party government and inject new tension into U.S.-U.K. relations.
On the 18th (local time), Trump took direct aim at U.K. Prime Minister Keir Starmer on his social media platform Truth Social, stressing that "the U.K. must not give up control of Diego Garcia in exchange for a 99-year lease." He called the current deal structure "at best precarious," urging Britain to "for whatever reason, not hand over this island." He added that if nuclear talks with Iran collapse, the base is essential to eliminate potential attack risks.
Diego Garcia is the largest island in the Chagos Archipelago in the Indian Ocean. It hosts a joint U.S.-U.K. military base. The United States entered into an agreement with Britain in 1966 and has used the island under a long-term lease. With long runways, the base sits about 5,200 km from Tehran and is considered an optimal location for military operations in the Middle East. During the wars in Afghanistan and Iraq, U.S. bombers flew from there, underscoring its strategic value.
But the island's history is entangled in a complex sovereignty dispute. It was originally part of Mauritius under French colonial rule, but became British after the Napoleonic Wars in 1814. When Britain granted independence to Mauritius in 1968, it carved out the Chagos Archipelago as the British Indian Ocean Territory. In the process, roughly 2,000 islanders were forcibly expelled between the late 1960s and early 1970s. In 2019, the International Court of Justice deemed Britain's occupation of the Chagos Archipelago unlawful and recommended returning the islands to Mauritius.
The Starmer government, under international pressure and seeking stable base operations, agreed to transfer sovereignty to Mauritius while keeping the base under a 99-year lease. Trump, however, maintains a hard line that sovereignty itself must remain with Britain. White House Spokesperson Karoline Leavitt said at a Wednesday briefing that the post should be taken as the Trump administration's official policy. The remark made clear that the president's direct intent takes precedence over working-level negotiations.
Reactions in British politics are mixed. Conservative shadow foreign secretary Priti Patel said Trump publicly rebuked, once again, what she called the Starmer government's unnecessary and costly capitulation on Chagos. By contrast, a U.K. Foreign Office Spokesperson reiterated that the deal is the only way to secure the future of the joint base and protect the British public. The British government sought to resolve legal uncertainty and ensure stable base operations through the agreement, but now finds itself in a bind after the U.S. president's public opposition.
The United States and Mauritius are scheduled to hold talks next week on Diego Garcia base security and cooperation. Experts say Trump's emphasis on peace through strength and his strong demands that allies retain strategic assets are likely to continue.