U.S., Denmark and Greenland Sign Arctic Security Deal Adding Two American Defense Areas

The agreement is signed—and the two locations are now confirmed

UNITED NATIONS — President Donald Trump, Danish Prime Minister Mette Frederiksen and Greenland Prime Minister Jens-Frederik Nielsen signed a trilateral Arctic security agreement Tuesday on the sidelines of the United Nations General Assembly in New York.

The signed agreement authorizes the United States to establish defense areas at Narsarsuaq in southern Greenland and Mestersvig in the east, according to the text released by Denmark and reviewed by the Associated Press. Narsarsuaq previously hosted an American installation; Mestersvig is a remote Danish outpost and airstrip.

That release resolves the central uncertainty in this report's September 21 update: the two locations are no longer merely source-reported plans. The governments have now signed an agreement that names them.

What the signed agreement permits

The agreement allows the United States to modernize and expand operations at the existing Pituffik Space Base and create the two named defense areas. It also permits additional defense areas by agreement and broad military movement, including undersea access, the Associated Press reports from the released text.

It directs Washington to use Greenlandic suppliers for goods and services connected to establishing, maintaining or dismantling the facilities to the maximum extent possible. That language creates a procurement preference; it is not evidence that contracts, budgets, troop totals or construction schedules have already been approved.

Trump said the United States would begin developing a larger military presence, including what he called two major bases. His announcement describes the administration's intended implementation, not proof that construction began Tuesday.

Greenland remains within the Kingdom of Denmark

The agreement stops short of Trump's earlier demand that Greenland become United States territory. Denmark and Greenland say it recognizes the sovereignty and territorial integrity of the Kingdom of Denmark and the Greenlandic people's right to self-determination.

Greenland Prime Minister Jens-Frederik Nielsen said the arrangement recognizes Greenland's interests and strengthens security for Greenland, Denmark, the United States and the wider Western alliance. Danish Prime Minister Mette Frederiksen said it would also support NATO and European security.

Nothing in the signed terms reported by Reuters and the Associated Press transfers ownership of Greenland to the United States. The accord is a defense arrangement—not a sale, annexation or grant of American sovereignty.

Non-NATO forces face restrictions

The released agreement says no non-NATO country may establish its own manned or unmanned military installation in Greenland or maintain a persistent military presence unless the parties agree otherwise, according to the Associated Press.

Trump described that restriction more broadly in his United Nations speech, saying no American adversary would be allowed a military presence or sensitive investment without United States approval. The speech is the president's characterization; the published defense restriction and any investment-review rules should be read according to their operative text.

The accord has no end date. The Associated Press reports that if Greenland becomes independent, it would remain in NATO and assume Denmark's rights and obligations under the agreement.

Why Pituffik Space Base matters

The United States currently operates Pituffik Space Base in northwestern Greenland. The installation supports missile warning, missile defense and space surveillance for the United States and NATO.

Greenland's position between North America, Europe and the Arctic makes it strategically important as the United States and its allies monitor Russian military activity and Chinese interest in the region. The announced restrictions on non-NATO bases and sensitive investments are aimed at keeping adversarial governments from gaining a strategic foothold.

The signing does not establish that either new defense area has received a public budget, construction contract, troop allocation or operating date. Those decisions require additional public details and implementation measures.

Trump's control claim is not a sovereignty transfer

Trump characterized the arrangement as giving the United States permanent control over Greenland's security. Denmark describes Arctic defense as a responsibility shared by NATO, while Denmark and Greenland continue to emphasize sovereignty, territorial integrity and self-determination.

Those descriptions are not legally interchangeable. Nothing in the reviewed official announcement says Greenland becomes American territory, gives the United States ownership of the island or makes NATO itself a signatory to the three-government agreement.

The agreement has been signed, but Denmark's September 18 announcement says entry into force remains subject to necessary national parliamentary procedures. No reviewed source provides a construction schedule, troop total, public budget or complete implementation timetable.

About the image

The accompanying image is an authentic April 4, 2023 U.S. Space Force photograph of a radar dome at Pituffik Space Base in Greenland. The Department of Defense credits Senior Airman Kaitlin Castillo; the federal-government image is in the public domain.

The file photograph shows an existing American military installation. It does not depict Tuesday's signing, the Narsarsuaq or Mestersvig defense areas, parliamentary proceedings or new construction.