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The new US–Denmark–Greenland agreement

On 22 September 2026 the governments of the United States, the Kingdom of Denmark, and Greenland (an autonomous territory of Denmark), signed a new agreement on the defence of Greenland.

The new agreement expands the US’s military presence in Greenland. It gives the US a right to block non-NATO countries from establishing a military presence in Greenland, and non-EU and non-NATO countries from making certain investments in the island. It also explicitly recognises NATO’s role in Arctic security and ensures that if Greenland became an independent nation, it would remain a member of NATO and the agreement would still apply (with Greenland taking on Denmark’s obligations).

The agreement followed months of negotiations. These began after a diplomatic crisis in January 2026 , when President Trump increased pressure on Greenland to become part of the United States, and initially refused to rule out the use of force to achieve this aim.

The crisis put a significant strain on the NATO alliance, of which the US and Denmark are both members. NATO’s European allies and Canada severely criticised President Trump’s approach. For more on these events see Commons Library research briefing: President Trump and Greenland: Frequently asked questions.

The 2026 treaty is an update of the 1951 Defense of Greenland agreement between the US and Denmark. Much of the substance of the original agreement remains in place.

What was in the 1951 agreement?

Both the US and Denmark (including Greenland) were founding members of NATO in 1949. Shortly after, the 1951 US-Denmark “Defense of Greenland” agreement recognised, in the context of the NATO alliance, that Denmark may need assistance from the USA in defending Greenland and allowed the US to establish military bases on the island. The agreement was updated in 1981 and again in 2004.

Specifically, the 1951 agreement:

• permitted the US, with Danish agreement on the basis of NATO plans, to establish and/or operate new “defence areas” (bases) on Greenland
• allowed the US to upgrade these facilities, station personnel and import equipment as required
• affirmed Danish sovereignty over Greenland
• obliged the US Government to cooperate fully with local authorities, and US nationals based there to respect local laws and customs
• permitted other NATO allies to use the defence areas to assist in the defence of Greenland

A 2004 update (the Igaliku Agreement) confirmed that the NATO Status of Forces Agreement had superseded some provisions in the 1951 agreement. The update established arrangements for Greenland’s home rule government to be consulted on matters relating to the defence areas, including any major changes to their facilities or operations.

What is new in the 2026 agreement?

The 2026 deal supplements, and in some places replaces, parts of the 1951 agreement. It allows for a larger US military presence in Greenland and gives the US the right to block non-NATO and non-EU countries from establishing a military presence or investing in Greenland. The agreement would continue to apply should Greenland become independent from Denmark.

The 2026 agreement does not have an end date and says it can only be amended by mutual consent (as per the 1951 agreement).

Expansion of the US military presence on Greenland

The 2026 agreement specifies that the US can:

• modernise and expand its activities at its existing Pituffik Space Base
• establish two new defence areas at Narsarsuaq (formerly host to a US base which closed in the 1950s) and Mestersvig (currently host to a Danish military dog sled patrol) with the details to be arranged between the three parties. See map below for their locations.
• establish additional defence areas and strengthen its existing military operations or facilities on Greenland

The US was already permitted to create additional defence areas under the 1951 agreement as set out above, but the 2026 agreement gives explicit permission for the expansion of Pituffik and two newly planned defence areas, as well as detailing further the consultation process for proposed new areas and their expansion.

The 2026 agreement also requires Denmark and Greenland to apply accelerated governmental approval procedures to US requests to establish unmanned military installations in Greenland outside of the defence areas.

It further codifies rights for US aircraft and sea vessels to enter and use Greenland and its territorial waters (for example, flying over it, landing and using undersea vessels).

In addition, the agreement requires the US to award all contracts for goods and services relating to the existing and new military facilities, including their construction, to Greenland sources, “to the maximum extent possible”.

Image by Reuters and Soren Jeppesen, with map data from OpenStreetMap

US role in blocking foreign investment and military bases in Greenland

The 2026 agreement mandates that all three parties (the US, Denmark and Greenland) must agree to any investment by a non-EU or non-NATO state or investors from such states. The requirement applies when the investment could result in control, significant influence or access to sensitive information that may pose a national security or public order risk within “Particularly Sensitive Sectors or Activities in the territory of Greenland (including the Territorial Waters)”.

The agreement says this will be achieved by Greenland applying investment screening laws “in close cooperation” with Denmark, and the Danish authorities engaging in “close consultation” with relevant US authorities. At present Greenland does not have a foreign direct investment screening scheme in place, though it proposed a scheme before withdrawing it in spring 2026. It will therefore have to propose and implement such a scheme as part of the implementation of the agreement.

The 2026 agreement also prevents any non-NATO state from establishing manned or unmanned military installations, or establishing a persistent military presence on Greenland, unless agreed by all three parties.

Danish obligations to secure bases, prevent espionage and strengthen Arctic military posture

The 2026 agreement commits the parties to ensure the security of the defence areas, including by monitoring the surrounding territory, and gives the US the right to raise concerns over new construction or change of use of buildings and facilities around the areas.

It also commits the parties to work together on counter-espionage in Greenland. It obliges Danish authorities to keep in close contact with their US counterparts “to the fullest extent necessary” to implement this obligation.

In addition, the agreement states that Denmark “shall continue to strengthen its security posture in the Arctic through comprehensive, multi-domain approach encompassing land, maritime, air and space capabilities”. It also commits Denmark to “address emerging threats and contribute to collective stability and security in the Arctic region”.

In January 2025, Denmark agreed with Greenland and the Faroe Islands (the other constituent part of the kingdom) to increase their investment in Arctic security, and supplemented that with a second agreement in October 2025, which included significant additional investments.

NATO’s role in Arctic security is also referenced in the new agreement. The agreement’s objectives reference the parties’ joint responsibilities to defend the North Atlantic Treaty Area, and article II of the agreement states that the parties “support a stronger NATO engagement in the Arctic, including as regards planning, presence, exercises, and joint intelligence gathering”.

Provisions for potential Greenland independence

If Greenland chooses to become an independent country at any point in the future, the agreement says Denmark and Greenland must work together to ensure the newly independent state agrees to remain in NATO and to assume Denmark’s obligations under the agreement, including any subsequent arrangements made under it. Greenland will also assume Denmark’s obligations under the 1951 agreement and the agreements amending and supplementing it (these are set out in full in annex 1 of the 2026 agreement).

For more on Greenland’s constitutional relationship with Denmark, and provisions for its independence see Library research briefing Greenland: Home rule, new international relations and US interest.

What have the US, Danish and Greenland governments said about the agreement?

Announcing the agreement on Truth Social, US President Donald Trump said it “gives the United States permanent control over security, and all other needs, in Greenland, completely addressing ALL of our many US concerns”. He said the US “will immediately begin the process of developing a large military presence in the appropriate part of Greenland, of which there are many”. He said further that the US “will FOREVER have the complete ability to do what is necessary in Greenland in order to secure and defend the security of Greenland, and the United States of America”.

Mr Trump said there would be “no cost to the United States”. It is unclear if he was referring to the costs of establishing the US’s new military bases on Greenland. Danish Foreign Minister Lars Løkke Rasmussen responded that “to the extent that the Americans are to build American bases in Greenland, that is of course something that the Americans finance”.

Ahead of the publication of the agreement the Prime Ministers of Greenland and Denmark released a joint press statement.

Prime Minister of Greenland Jens-Frederik Nielsen said it was “encouraging” that an agreement was being made that “will ensure and strengthen the security of Greenland, the Kingdom of Denmark, the United States, and the Western Alliance”. He said the agreement “recognises Greenland’s interests and our place in the international cooperation. It is to the benefit of us all”.

Prime Minister of Denmark Mette Frederiksen said she was “glad” that the parties had made the agreement, and that it “strengthens our common security in the Arctic and the North Atlantic Area and therefore is great for NATO and Europe as well”. She said it also recognises “the sovereignty and territorial integrity of the Kingdom and the Greenlandic people’s right to self-determination”.

What have the UK and other NATO allies said?

The US and Denmark’s allies have welcomed the new agreement.

UK Prime Minister Andy Burnham held a call with his Danish counterpart on 20 September in which he congratulated Ms Frederiksen on “negotiating a deal benefitting the US, Greenland and Denmark”, and both were said to have welcomed “the US’ commitment to the region and underlined the strategic and shared importance of the High North for Euro-Atlantic security”. Defence Secretary Wes Streeting also welcomed the agreement, saying “it will strengthen Arctic security and security in the North Atlantic” and that “a secure High North underpins UK security and NATO security”.

NATO Secretary General Mark Rutte said “it was great to see” the new agreement. “Greater security in the Arctic and North Atlantic is essential for Europe and North America alike”, he added, and “this agreement, along with NATO’s growing role in securing this vital region, enhances our collective security and supports a safer and more stable future for us all”.

French President Emmanuel Macron said the agreement helped “to reaffirm Danish sovereignty” over Greenland. Calling it a “good thing” he said, “I simply note that Danish sovereignty is respected, that international law is respected, and that this is what we were asking for”.

German Chancellor Friedrich Merz said it was “good news for the security of Greenland” and that the agreement “strengthens our partnership in Nato and security in the High North”.

What does this agreement mean for the NATO alliance and Arctic security?

NATO says that the Arctic and the High North have become increasingly important for its collective defence and that it will strengthen its focus on the region. It says the Arctic is “a gateway to the North Atlantic, hosting vital trade, transport and communication links between North America and Europe”. The security of the Greenland–Iceland–UK Gap (GIUK) is particularly important to the UK.

Commentators have noted that the 2026 agreement recognises this. Connor McPartland, writing for the Atlantic Council, notes that “the agreement explicitly highlights the role of NATO in Arctic security”. Former US Assistant Secretary of Defense, Deborah Rosenblum, said the new agreement “very artfully” brings NATO into the US–Denmark defence relationship, “ensuring that any activity that would occur at subsequent defence areas that the United States would build out would be for the sake of NATO as well as the North Atlantic area”.

Commentators have suggested the planned new military installations on Greenland can also strengthen the wider NATO alliance. Commenting on the potential new US airfields on Greenland, Ms Rosenblum said that the US military had identified a need for more airfields in the High North that can host a range of US aircraft, as that’s the region where there had been “very aggressive behaviour on the part of the Russians toward a lot of the NATO allies”. She also highlighted that the increased US presence could provide greater capacity for training and military exercises with NATO allies aimed at the High North.

The expansion of US military capabilities, and how that might affect the alliance has also been discussed. Julianne Smith, former US Permanent Representative to NATO, noted that one of the new planned US military bases will be a deepwater port, giving US submarines access to Greenland for the first time.

Ms Smith and Ms Rosenblum also discussed the possibility of Greenland hosting part of the proposed US “Golden Dome” air and missile defence system. The preamble of the 2026 agreement referenced the parties’ shared interest in the US having military access to Greenland “including through establishment of a Golden Dome defence system”. Preambles to treaties are generally not legally binding but can be used in legal interpretations of the agreement. The Australian Strategic Policy Institute explored the importance of Greenland to the Golden Dome system in January 2026.

For more on Greenland’s role in Arctic security see Commons Library research briefing UK defence: Renewed interest in the Arctic.

What happens next?

The agreement will come into force when the Danish Government informs the US that it and Greenland have both completed their necessary parliamentary procedures.

The US Government does not require congressional approval for the 2026 deal. The 1951 agreement that it’s based on was treated as an “executive agreement” by the US Government (as it came under the auspices of the 1949 North Atlantic Treaty). Executive agreements, unlike treaties, do not require Senate approval before the US Government can ratify them.