Greenland will stay part of the Kingdom of Denmark under a security deal it plans to sign with Denmark and the U.S. in New York next week, Danish and Greenlandic leaders said on 18 September.

Donald Trump posted on Truth Social at 17:18 U.S. Eastern time the same day that the U.S. had entered into an agreement giving it "permanent control over security, and all other needs, in Greenland." Nobody has signed anything yet, and the text hasn't been published. Denmark and Greenland said they wouldn't comment further.

Trump had spent months demanding control of Greenland, which he said the U.S. needed for national security. What Denmark and Greenland describe is a defence pact that keeps the island Danish and adds to military rights the U.S. has held there since 1951.

Fact-check of Trump's post

Trump wrote that the U.S. had already entered into the agreement. It hasn't. The Danish and Greenlandic statement says the three governments expect to sign next week, and that the deal then has to pass the Danish and Greenlandic parliaments before it takes effect.

Trump wrote that the U.S. now permanently controls security in Greenland. Denmark's Self-Government Act of 2009 keeps foreign, defence and security policy for Greenland with the Danish government and parliament, and neither Denmark nor Greenland has said the deal changes that. Mette Frederiksen, Denmark's prime minister, said the deal recognises the Kingdom's sovereignty and territorial integrity.

Trump wrote that the deal covers all of the U.S.'s other needs in Greenland as well. Neither the Danish and Greenlandic statement nor the State Department official's account, as reported by Reuters, names any need beyond defence and investment.

Trump wrote that the deal gives the U.S. a say over sensitive investments by its adversaries in Greenland. Frederiksen and Jens-Frederik Nielsen, who leads Greenland's government, didn't mention it. The New York Times reported that Denmark and Greenland fought a U.S. veto on investment during the talks, according to the Danish outlet POV International.

Trump wrote that the deal costs the U.S. nothing. In the same post, he promised to start building a large military presence on the island right away. He didn't say who would pay for it, and neither did anyone else.

Trump called the deal an agreement with no end. The 1951 agreement has no fixed end either. Article XIV keeps it in force for as long as the North Atlantic Treaty lasts.

Trump wrote that for more than 100 years, no president had been able to do anything about Greenland. Franklin D. Roosevelt's government signed the 1941 agreement that put U.S. forces on the island. Harry Truman's signed the 1951 treaty that still governs them, and George W. Bush's signed the 2004 update.

What the U.S. gets

Reuters, CBS News, NPR and Axios, drawing on Trump's post and an unnamed State Department official, reported the main U.S. terms. The U.S. would get permanent access to Greenland, the right to base forces and fly over the island, and room to build what the official called a significant military presence.

Countries outside NATO would be barred from building military bases in Greenland, the same reports said.

The deal has no end date and would survive Greenlandic independence, the State Department official told Reuters.

Marco Rubio, the U.S. secretary of state, said Greenland would forever sit inside North America's strategic defence area, closed to any adversary, NPR reported.

What Denmark and Greenland keep

Denmark keeps sovereignty over every part of Greenland, including any ground U.S. forces use. Frederiksen said the deal recognises "the Greenlandic people's right to self-determination."

Troels Lund Poulsen, Denmark's defence minister, drew that line in January, when the talks started. "We will not cede sovereignty over parts of the kingdom," he said.

Greenland's government can't sign defence or security treaties by itself. The Self-Government Act reserves that power to the Danish state. Greenland runs most of its domestic affairs, and it took over its mineral resources in 2010.

Section 21 of the same law lets Greenlanders choose independence. That would take a referendum and the consent of both Inatsisartut, Greenland's parliament, and the Folketing, Denmark's parliament.

Both parliaments also have to approve this deal. Múte Bourup Egede, Greenland's foreign minister, told broadcaster KNR that Inatsisartut must ratify it first.

Nielsen said the deal recognises Greenland's interests and its place in international cooperation.

Rights the U.S. has held since 1951

Denmark and the U.S. signed the Defence of Greenland Agreement in Copenhagen on 27 April 1951. Every U.S. base on the island has operated under it since.

Article II lets the U.S. set up and run defence areas in Greenland that Denmark can't run alone. Inside them, U.S. forces can build and operate facilities, station troops and store supplies. Both countries' flags fly over each area. Denmark can attach an officer to the U.S. commander's staff, and the commander has to consult that officer on important local matters.

Article V lets U.S. ships and aircraft move freely between the defence areas, with no compulsory pilotage and no harbour dues.

Article VIII gives the U.S. the right to exclusive jurisdiction over the defence areas it runs. Article VI requires U.S. forces to respect local laws and customs. Article VII frees U.S. personnel and supplies from Danish customs and taxes.

Article XIV keeps the agreement in force "for the duration of the North Atlantic Treaty." As long as both countries stay in NATO, the 1951 rights have no end date.

Gen. Gregory Guillot, who leads U.S. Northern Command, said in April that "we don't really need a new treaty," The New York Times reported.

The 2004 Igaliku amendment

Denmark, Greenland and the U.S. updated the 1951 agreement at Igaliku, in southern Greenland, on 6 August 2004. Greenland's Home Rule government signed as a full party for the first time.

Igaliku made Thule Air Base the only defence area in Greenland. The U.S. agreed to consult and inform Denmark and Greenland before any significant change to its forces or facilities there. Consultation isn't a veto.

Greenland's flag has flown over the base next to the Danish and U.S. flags since then. Igaliku also cleared software and minor hardware upgrades to the base's radar for U.S. missile defence, and joint declarations promised U.S. economic, technical and environmental cooperation with Greenland.

Pituffik Space Base

Thule became Pituffik Space Base on 6 April 2023 and is run by the U.S. Space Force. About 150 U.S. service members were stationed there permanently as of 2025. Its 12th Space Warning Squadron runs a ballistic missile early warning radar, and the base provides missile warning, missile defence and space surveillance for the U.S. and NATO.

Pituffik is the last U.S. base in Greenland. The U.S. once had installations across the island, including Narsarsuaq in the south and Kangerlussuaq in the south-west, and left them decades ago.

The New York Times reported in April that the U.S. was negotiating access to three more sites, including Narsarsuaq and Kangerlussuaq, under the 1951 agreement.

Other agreements on Greenland

Henrik Kauffmann, Denmark's envoy in the U.S., signed Greenland's first defence deal with Secretary of State Cordell Hull on 9 April 1941, a year to the day after Nazi Germany invaded Denmark. The U.S. took on Greenland's defence and supply and built airfields, radio stations and ports. The 1951 agreement replaced it.

A 1960 agreement let the U.S. build and run nuclear reactors in Greenland for research and power. The reactor at Camp Century, a base dug into the ice sheet, shut in 1964. The agreement allowed radioactive wastewater to be released into the ice.

Greenland's Home Rule government took over Kangerlussuaq and Kulusuk airports in 1991. A permanent committee of the three governments was set up the same year to handle military matters.

Greenland and the U.S. signed a memorandum on mining cooperation in 2019. The U.S. announced USD 12.1 million for Greenland's resource sector, tourism, business and education in 2020.

Denmark signed its own Defence Cooperation Agreement with the U.S. on 19 December 2023. It lets U.S. forces use the Karup, Skrydstrup and Aalborg air bases in Denmark, and it doesn't cover Greenland or the Faroe Islands. The Folketing approved it in June 2025.

Denmark's forces in Greenland

Denmark's Joint Arctic Command, based in Nuuk, runs Danish military operations around Greenland and the Faroe Islands. Its forces include the Sirius Patrol, a dog-sled unit in north-east Greenland, and Thetis-class and Knud Rasmussen-class patrol ships.

Denmark agreed DKK 14.6 billion in Arctic defence spending on 27 January 2025. The money buys three new Arctic naval vessels, two long-range drones, more satellite capacity and more places in Arctic military training for young Greenlanders.

Denmark added DKK 27.4 billion on 10 October 2025, for maritime patrol aircraft, two more Arctic vessels, icebreaker access, an undersea cable, an air surveillance radar for east Greenland, drones, a new military unit in Greenland and a new Arctic Command headquarters in Nuuk. Both packages were drawn up with the Greenlandic and Faroese governments.

How the deal came together

JD Vance and Rubio met Danish Foreign Minister Lars Løkke Rasmussen and Greenland's then foreign minister, Vivian Motzfeldt, at the White House on 14 January 2026. Løkke Rasmussen said afterwards that a "fundamental disagreement" with Trump remained.

Denmark, Greenland and the U.S. set up a working group at the talks. Løkke Rasmussen said it would deal with U.S. security concerns while respecting Denmark's red lines.

Trump and Mark Rutte, NATO's secretary-general, agreed the outline of a future deal later that month, and Trump dropped threatened tariffs on European allies. NATO said Rutte had offered no compromise on sovereignty.

What happens next

The three governments plan to sign in New York during the UN General Assembly next week. The deal then goes to the Folketing and Inatsisartut, and it can't take effect until both pass it.