In a watershed moment for Arctic security, leaders from the United States, Denmark, and Greenland have signed a landmark updated defense agreement that clears the way for two new U.S. military installations on the semi-autonomous Arctic territory, while formally reaffirming Denmark’s long-held sovereignty over the region. The signing ceremony took place on the sidelines of the United Nations General Assembly in New York, where U.S. President Donald Trump was joined by Danish Prime Minister Mette Frederiksen and Greenlandic Prime Minister Jens-Frederik Nielsen to formalize the pact.
Right before the signing, Trump announced that work to develop the expanded U.S. military footprint would begin without delay, telling reporters “we will immediately begin the process of developing a large military presence in the appropriate locations”. All three leaders framed the deal as a mutually beneficial outcome. Frederiksen noted the agreement serves the interests of not just the three signatory parties, but also Europe and the broader NATO alliance, while Nielsen called the outcome an unambiguous “win-win-win”.
The agreement brings a close to more than 18 months of rising geopolitical tension over Greenland, sparked last year when Trump publicly threatened to seize the territory over stated U.S. national security concerns, highlighting its critical strategic location in the Arctic and abundant untapped mineral reserves. His aggressive rhetoric drew widespread condemnation from Greenlandic officials, the Danish government, and other European leaders, who issued a joint rebuke arguing that his threats undermined transatlantic cooperation and risked triggering a dangerous escalation in the region.
This new deal amends and modernizes the original 1951 bilateral defense agreement between Denmark and the U.S. that has governed U.S. military activity in Greenland for 75 years. Under the terms of the updated pact, the U.S. gains permission to establish two new designated defense areas at Narsarsuaq in southern Greenland and Mestersvig on the island’s eastern coast. U.S. Northern Command has confirmed that U.S. military survey teams have already assessed Narsarsuaq, a former World War II military base and decommissioned civilian airport that already offers deep-water port access and a fully functional large runway. Mestersvig, by contrast, is a remote, barely developed outpost currently used only by a Danish naval dog sled patrol unit.
Critical details of base construction and operations, outlined as “modalities and technical details” in the agreement, have not yet been finalized and require mutual approval from all three signatory parties, meaning U.S. activity in Greenland is not unlimited and cannot proceed without formal consent from Copenhagen and Nuuk.
The U.S. already maintains Pituffik Space Base in northwestern Greenland, and the new agreement allows the U.S. to upgrade and expand its existing operations at that site. A key non-proliferation clause bars any non-NATO member state from constructing manned or unmanned military installations on Greenland, or maintaining a permanent military presence on the island. While this provision is explicit in the updated text, military access for non-allied nations was already effectively prohibited prior to the deal.
Notably, the agreement involves no cession of territory to the United States, and Washington explicitly recognizes both Denmark’s full sovereignty and territorial integrity over Greenland, as well as Greenland’s constitutionally protected right to self-determination. This represents a clear retreat from Trump’s earlier public calls to acquire the Arctic island, but still delivers on his core goal of expanding U.S. military influence in the increasingly strategic Arctic region, a outcome that is already being framed as a major policy win among many U.S. political circles.
Before the deal can enter into force, it must still receive formal ratification from both the Danish parliament and Greenland’s legislative assembly.
Despite months of acrimonious public tension over the territory, the atmosphere at Tuesday’s signing was uniformly cordial and optimistic. Trump praised the pact, saying “We going to have a tremendous relationship, a secure relationship. This is tremendous for Europe and for the United States, for everybody, and for Greenland it’s going to be incredible.”
Frederiksen framed the signing as a major milestone in the long-standing transatlantic defense partnership between the two nations, noting “Seventy-five years ago we entered into an agreement about the defence of Greenland. Today, we’re signing an even bigger and better agreement – a deal that can last forever.” She reiterated that the agreement fully upholds Danish sovereignty and Greenlandic autonomy.
For his part, Nielsen emphasized that this agreement was negotiated with Greenlandic input at its core, saying “for Greenland, it is not only an agreement about us, it is an agreement with us. It takes into account the people of Greenland, our rights, our livelihoods and the development of our country. Greenland matters for North American security and for transatlantic security.” Nielsen also highlighted NATO’s central role in maintaining stability in the North Arctic amid a shifting global security landscape. The agreement also includes a provision confirming that Greenland would retain its NATO membership if it achieves full independence from Denmark in the future.
The original 1951 agreement already allowed the U.S. to deploy as many military personnel to Greenland as it deemed necessary, and the U.S. currently stations more than 100 permanent troops at Pituffik Space Base. For months, Trump pushed for a move to purchase or annex Greenland, arguing the territory was vulnerable to growing influence from U.S. strategic rivals Russia and China. He also framed control of Greenland as critical to his proposed “Golden Dome” national missile defense system, though the new deal only mentions the project once and includes no binding commitments to advance it.
Shortly after the signing, a NATO spokesperson issued a statement welcoming the agreement, noting that it would “help advance security, stability and cooperation in this vital region”. In Denmark, the deal has been broadly celebrated as a major diplomatic success, with multiple major political parties already announcing they will support ratification. For Greenland, a territory of just 56,000 people, the agreement brings a welcome end to months of political uncertainty. By securing formal recognition of its autonomy and sovereignty alongside the expanded defense cooperation, Greenlandic leaders have emerged from the standoff with a deal that addresses their core priorities, bringing a long period of geopolitical crisis to a close.