US President Donald Trump has linked his push to annex Greenland with criticism of the UK’s Chagos Islands handover to Mauritius, calling it “great stupidity” in a Truth Social post targeting PM Keir Starmer, reversing US endorsement from 2025. US President Donald Trump has linked his push to annex Greenland with criticism of the UK’s Chagos Islands handover to Mauritius, calling it “great stupidity” in a Truth Social post targeting PM Keir Starmer, reversing US endorsement from 2025.