U.S. President Donald Trump, in a significant policy reversal, publicly denounced the United Kingdom's recent Chagos Islands deal with Mauritius as an "act of total weakness" and "great stupidity" on Tuesday, January 20, 2026. Speaking via his Truth Social platform, Trump linked this decision to his renewed emphasis on acquiring Greenland, arguing that the UK's move demonstrated a lack of strength noticed by global rivals like China and Russia. This strong criticism marks a stark departure from his administration's earlier stance. In May 2025, then-Secretary of State Marco Rubio had welcomed the agreement, hailing it as a "historic achievement" that guaranteed the long-term, stable operation of the crucial joint U.S.-UK military facility on Diego Garcia, the largest island in the Chagos Archipelago. The deal, struck in October 2024 and formalized in May 2025, involved Britain transferring sovereignty of the islands to Mauritius while leasing back the Diego Garcia base for 99 years at an annual cost of £101 million. The UK government swiftly defended its position, stating that the agreement was the best option to secure the future of the military base for generations, ensuring its unique capabilities remain intact and deterring adversaries. British senior minister Darren Jones affirmed that the treaty has been signed and cannot now be changed. The deal had previously garnered support from various international partners, including Australia, New Zealand, and notably, India, which views the Indian Ocean region as its sphere of influence and has cooperated closely with Mauritius. Trump's unexpected comments create diplomatic strain, particularly for UK Prime Minister Keir Starmer, who had recently sought to de-escalate tensions with the U.S. over the Greenland issue. The strategically vital Diego Garcia base continues to be an indispensable platform for security operations across the Middle East, South Asia, and East Africa.