The United States, Denmark and Greenland signed on Tuesday, 22 September 2026, a security agreement that expands the US military presence on the island.

The signing took place on the sidelines of the 81st United Nations General Assembly in New York, by Donald Trump, Danish Prime Minister Mette Frederiksen and Greenland Prime Minister Jens-Frederik Nielsen. According to Reuters, in a dispatch carried by The Jerusalem Post, the text authorises bases at Narsarsuaq in the south and Mestersvig in the east, expands the Pituffik base, which serves as a missile early-warning site, and lets US aircraft overfly, land and operate anywhere in Greenland, including its territorial waters and undersea space. No non-NATO country may keep a “persistent” military presence without unanimous approval by all three parties. The deal has no expiry date and amends the 1951 defence treaty. Trump said the agreement gives the United States “permanent control over security and all other needs” on the territory, and that no adversary will be allowed to establish a military presence there. Frederiksen said the text respects “the territorial integrity of the Kingdom of Denmark, as well as Greenland’s right to self-determination”, according to Al Jazeera, which quoted Nielsen saying “it is vital to keep NATO strong”. The deal ends months of standoff after Trump refused to rule out military or economic force to take the island, triggering a diplomatic crisis inside the alliance in January 2026. The US military presence in Greenland shrank from 17 installations and more than 10,000 personnel during the Cold War to about 200 at Pituffik.