US President Donald Trump said on Tuesday, January 20, that Britain’s decision to transfer sovereignty of Diego Garcia in the Chagos Islands to Mauritius was a sign of “total weakness.” He argued that the move reinforced national security concerns and cited it as another reason why the United States should acquire Greenland.

Diego Garcia hosts a key US-UK military air base in the Indian Ocean. Under an agreement reached last year, Britain agreed to hand sovereignty of the Chagos Islands to Mauritius while retaining control of the base through a long-term lease. At the time, the US administration welcomed the deal, praising efforts to ensure the continued operation of the joint military facility. Reacting strongly, Trump wrote on his Truth Social platform that the UK was planning to give up Diego Garcia, home to a crucial US military base, to Mauritius “for no reason whatsoever.” He added that China and Russia would undoubtedly be paying close attention to Britain’s actions.

British senior minister Darren Jones defended the agreement, saying it was the most secure option for the base, allowing it to function for the next century. He confirmed that the treaty had already been signed and could not be altered, emphasizing that Britain would rely on diplomacy and the prime minister’s relationship with the US president to safeguard national interests.

Although Prime Minister Keir Starmer has previously built a strong rapport with Trump, including securing a deal to reduce certain tariffs, tensions have recently emerged over Trump’s stance on Greenland and his criticism of the Diego Garcia agreement. Trump has repeatedly claimed that growing Chinese and Russian influence makes Greenland essential to US security and has insisted on full ownership. Britain’s agreement with Mauritius had been delayed following Trump’s inauguration in January 2025, as London allowed the new US administration time to review the arrangement.