World leaders at the United Nations General Assembly have unanimously approved the first declaration on sea level rise, protecting the sovereignty of island nations threatened by rising oceans. The agreement says countries like Tuvalu, the Marshall Islands, the Maldives and Kiribati will keep their statehood, UN membership and maritime boundaries even if their land disappears beneath the waves. It establishes a presumption in favour of continued statehood and protects exclusive economic zones, preserving rights over fishing, energy and seabed resources. The United States did not block the text. Championed by the Alliance of Small Island States after years of campaigning, the declaration calls on wealthy, high-emitting nations to urgently expand adaptation finance for vulnerable states, though it pledges no new money. 'Sea level rise is measured in millimetres, but its toll is measured in millions of shattered lives,' UN chief Antonio Guterres told the meeting. A UN report has warned that up to 1.2 billion people could be displaced by 2050.