UNITED NATIONS — The United States, Denmark, and Greenland signed a trilateral security agreement on September 22, 2026, allowing Washington to establish two new military bases in Greenland and deploy a missile defense system. The deal, signed on the sidelines of the UN General Assembly in New York, marks a significant expansion of US military infrastructure in the Arctic while reaffirming Danish sovereignty over the semi-autonomous territory.
Key developments
The agreement permits the US to modernize and expand its presence at Narsarsuaq in southern Greenland and Mestersvig on the east coast, in addition to the existing Pituffik Space Base in the northwest. The pact also includes provisions for the Golden Dome missile defense system, which will be deployed in Greenland to counter ballistic missile threats. US aircraft and vessels will gain broad access to Greenland’s territorial waters and airspace under the terms of the deal.
Reaffirmation of sovereignty and self-determination
Despite the expanded US military footprint, the agreement explicitly reaffirms the sovereignty and territorial integrity of the Kingdom of Denmark and Greenland’s right to self-determination. Danish Prime Minister Mette Frederiksen described the pact as a "deal that can last forever," emphasizing its benefits for NATO and the broader transatlantic alliance. Greenland’s Prime Minister Jens-Frederik Nielsen and US President Donald Trump also expressed satisfaction with the agreement during the signing ceremony.
Greenlandic reactions: Relief and lingering skepticism
Greenlandic officials and residents expressed relief that the deal averts the prospect of a US annexation of the territory, which Trump had previously floated. Naaja Nathanielsen, a Greenlandic MP in the Danish parliament, called the outcome "very sensible" and urged households to raise the Greenlandic flag in celebration. However, she acknowledged that skepticism remains due to past US military presence and geopolitical tensions.
Activist Orla Joelsen encouraged residents in the capital Nuuk to welcome the Greenlandic leadership upon their return from New York, where the deal was finalized. The agreement stops short of Trump’s earlier demand for a US takeover of Greenland, which had sparked diplomatic friction with Denmark.
Historical context and strategic implications
The US first established military bases in Greenland during World War II, maintaining up to 17 installations and 10,000 personnel during the Cold War to monitor Soviet activity. Today, only Pituffik Space Base remains operational, with approximately 150 US military personnel. The new agreement represents a renewed US focus on the Arctic, driven by concerns over Russia’s and China’s growing presence in the region.
Trump framed the deal as giving the US "permanent control" over Greenland’s security, stating that "no US adversary will ever be permitted to establish a military presence in Greenland" without US approval. The agreement also includes restrictions on foreign investment in Greenland, aimed at preventing adversaries from gaining economic or military footholds on the island.
Long-term implications and future flexibility
The pact allows for additional US military sites in Greenland, subject to mutual agreement among the three parties. It also accounts for Greenland’s potential future independence, ensuring the agreement remains applicable regardless of Greenland’s political status. Danish officials emphasized that the deal strengthens NATO cohesion and addresses security concerns without compromising Greenland’s autonomy.
The agreement follows months of behind-the-scenes negotiations between US, Danish, and Greenlandic officials, aimed at balancing security imperatives with the sensitivities of Greenland’s population and Denmark’s sovereignty claims.