President Donald Trump signed a new security agreement Tuesday with the prime ministers of Denmark and Greenland on the sidelines of the United Nations, ending months of diplomatic turbulence over the Arctic island territory. The deal amends and supplements a 1951 defense treaty between the United States and Denmark, adding provisions for expanded U.S. military access, two new American bases, and restrictions barring non-NATO countries from establishing a military presence in Greenland.

The two planned bases will be located at Narsarsuaq in southern Greenland — the site of the former American Bluie West One base that closed in the 1950s — and at Mestersvig in eastern Greenland, currently home to Denmark's Sirius Dog Sled Patrol unit. The U.S. military will also gain free access to air, land, and sea routes between the two facilities, and fast-track approval processes will be established for potential drone warfare installations, though Denmark and Greenland retain final authority over where such facilities are built. Greenland already hosts the Pituffik Space Base, where approximately 150 American troops operate a ballistic missile monitoring site.

Defense analysts described the practical military expansion as modest. Mark Cancian, a senior adviser at the Center for Strategic and International Studies, estimated the total troop increase could be fewer than 50 personnel, despite Trump's description of the deal as the beginning of a 'large military presence.' The restrictions on non-NATO nations are widely seen as directed at China and Russia, and the agreement also includes provisions ensuring continued U.S. military access in the event Greenland becomes independent from Denmark — a contingency that had not been addressed in the original treaty.

The deal is a notable departure from early 2025, when Trump threatened to take Greenland by force and imposed tariff threats on European nations that objected. European allies, alarmed by the rhetoric, held discussions about the future of transatlantic security arrangements without U.S. participation. Former Biden administration official Iris Ferguson told CNN the episode caused significant damage to Arctic security cooperation, though she said the new agreement moves toward advancing shared goals.

The agreement still requires ratification by Danish and Greenlandic lawmakers before taking full effect. The deal also references Trump's proposed 'Golden Dome' missile defense system, though that program remains years from completion. Analysts noted that the core framework largely codifies arrangements already permitted under the 1951 treaty, with one significant procedural distinction: Greenland itself is now a named signatory to the agreement.