U.S. gains broad land, air and sea access under Greenland defence deal

US President Donald Trump (R), Denmark’s Prime Minister Mette Frederiksen (C) and Greenland’s Prime Minister Jens-Frederik Nielsen (L) arrive to sign a trilateral security deal on the sidelines of the 81st United Nations General Assembly in New York, on September 22, 2026. (Brendan Smialowski/AFP via Getty Images)

The new defence agreement signed by the United States, Denmark and Greenland in New York on Tuesday will expand American military presence across the Arctic island, including access to its airspace and territorial waters.

It also allows the U.S. to establish two new defence areas: Narsarsuaq, the site of the former Bluie West One U.S. air force base, in southern Greenland; and Mestersvig, an outpost used by the Sirius Dog Sled Patrol, a Danish military unit, in eastern Greenland.

In addition, the U.S. will be allowed to modernize and expand its activities at Pituffik Space Base on Greenland’s northwestern coast, approximately 1,200km north of the Arctic Circle.

The U.S. can also propose additional defence areas “for the defence of the North Atlantic Treaty area, Greenland, and the American continent,” under the deal, but their location, size and activities would have to be agreed on with Greenland and Denmark.

Non-NATO countries will also be blocked from setting up manned or unmanned military installations on the island without the agreement of Washington, Nuuk and Copenhagen.

“Strengthening our common security,” says Denmark PM

Danish Prime Minister Mette Frederiksen said the agreement was an important show of unity as geopolitical tensions rise in the Arctic.

“We are strengthening our common security, boosting our common deterrence, showing our adversaries who we are, and we are doing it together,” she said at the signing.

U.S. President Donald Trump floated the idea of buying Greenland from Denmark during his first administration, with Denmark and Greenland replying that the island wasn’t for sale.

During his current second term, he ratcheted up the pressure by refusing to rule out military force, arguing that the U.S. needed Greenland for national security because of growing Russian and Chinese activity in the Arctic.

In an address to the United Nations on Tuesday before signing the new deal, Trump called Greenland “strategically vital” and said the agreement would expand America’s footprint in the Arctic and strengthen NATO.

Limits on investment in sensitive sectors

Under the new agreement, U.S. forces can travel freely by land, air and sea between its defence areas on the island. American military aircraft will also be allowed to fly over and land elsewhere in Greenland, with U.S. vessels permitted to travel underwater within Greenlandic territorial waters, unless the three governments agree to restrictions.

The deal also requires Greenland to prevent investors from countries outside NATO, its partner countries and outside the EU, from gaining control, significant influence or sensitive information in sectors where that could threaten national security or public order.

“The security landscape in the Arctic is changing and we recognize the long-term security threats that you, Mr. President, have rightly spoken about,” Greenland Prime Minister Jens-Frederik ​Nielsen said at the signing with Frederiksen and Trump. 

“This agreement should put to rest any doubt today, and in the future, about where Greenland’s loyalty lies. Our commitment to this alliance and the security we’ve built together is not in question.” 

Provisions for potential Greenlandic independence

The new deal amends and supplements the 1951 defence agreement governing U.S. military presence in Greenland. The new agreement doesn’t have an end date and can only be changed if Copenhagen, Nuuk and Washington agree.

If Greenland eventually becomes independent, the agreement says the Danish and Greenlandic governments will ensure that the new state agrees to remain in NATO and that it will take over Denmark’s rights and obligations under the deal.

The agreement must now go through the Danish and Greenlandic parliaments.

Related stories from around the North: 

CanadaArctic would be “flagship project” in proposed EU-Canada partnership, von der Leyen says, Eye on the Arctic

Denmark: Trump touts ‘permanent control’ in Greenland deal as Denmark, Nuuk stress sovereignty, self-determination, Eye on the Arctic

Greenland: Timeline-Key moments in Trump’s push to control Greenland, Reuters 

Russia: Kremlin says Greenland deal with US and Denmark is a matter for those involved, Reuters

United States:  New Greenland military bases will expand U.S. Arctic footprint, enhance NATO, Trump tells UN, Eye on the Arctic