The US will expand its military presence in Greenland under the new security agreement.
The deal keeps Greenland under Danish sovereignty despite Trump's earlier push to acquire the island.
The agreement strengthens US and NATO security cooperation in the strategically important Arctic.
US President Donald Trump, Denmark and Greenland have signed a security agreement allowing the United States to expand its military presence on the Arctic island, easing a months-long dispute without transferring sovereignty to Washington.
The agreement, signed at the United Nations in New York on Tuesday, September 22, allows the US to expand its existing military presence and establish additional defence areas at Narsarsuaq in southern Greenland and Mestersvig on the east coast. It also provides for a US “Golden Dome” missile-defence system and bars states that are not NATO members from establishing their own military installations or maintaining a persistent military presence on the island, unless otherwise agreed.
The deal marks a shift from Trump's earlier demand that Greenland become part of the United States. For months, the US president had argued that American control of the island was necessary for national security and had refused to rule out military or economic pressure to achieve it. The agreement instead keeps Greenland within the Kingdom of Denmark while giving Washington a substantially larger role in its defence.
What does the agreement actually do?
The agreement is primarily about military access and Arctic security, rather than ownership of Greenland.
The US already operates Pituffik Space Base in north-western Greenland, a facility used for missile warning, missile defence and space surveillance. The new arrangement expands the scope of America's military presence and amends the 1951 US-Danish defence agreement that provides the legal basis for the American presence on the island.
Two additional locations are central to the deal. Narsarsuaq was previously used as a US military base during the Cold War, while Mestersvig is currently used by Denmark's Sirius Dog Sled Patrol.
Reuters reported that the agreement allows the US to establish additional defence areas at Narsarsuaq and Mestersvig. Trump said the United States would build “two very major military bases”, while the agreement itself refers to the locations as defence areas.
The arrangement also provides for a “Golden Dome” missile-defence system in Greenland. The island's location is important to US military planning because it sits between North America and Europe and along Arctic routes that are increasingly significant to the defence of the North Atlantic.
The agreement also bars non-NATO countries from establishing their own manned or unmanned military installations or maintaining a persistent military presence in Greenland, unless otherwise agreed. It also restricts certain investments and activities by states or investors from outside NATO, NATO partner countries and the EU in particularly sensitive sectors.
Does this mean the US controls Greenland?
Greenland is a self-governing part of the Kingdom of Denmark, and Denmark retains sovereignty over the island. The agreement does not transfer ownership of Greenland to Washington.
That is the key distinction between the agreement and Trump's earlier position.
Trump had repeatedly said the United States should acquire Greenland and described American control of the island as necessary for US security. Trump had also refused to rule out military action, creating tensions with Denmark, a fellow NATO member.
Under the agreement, Washington instead receives expanded military access and a long-term role in Greenland's security.
Trump has described the arrangement differently. In his UN speech, he said it gives the US “permanent control over security and all other needs” in Greenland. Danish officials have described it differently, emphasising that the arrangement preserves Danish sovereignty and Greenlanders' right to self-determination.
The Wall Street Journal reported that the agreement still requires parliamentary approval before it can take effect, meaning the signing is an important step but not the end of the implementation process. Danish officials have also stressed that the arrangement preserves the existing sovereignty structure.
The difference in language matters. The US is gaining a larger role in Greenland's defence and greater military access, but that is not the same as acquiring sovereignty over the territory.
Why is Greenland so important to the US?
Greenland's strategic value comes largely from its geography.
The island lies between North America and Europe and occupies a position connecting the Arctic and North Atlantic. That makes it useful for monitoring air and maritime activity, detecting missile threats and supporting military operations in the region.
The Arctic has also become more strategically contested as declining sea ice makes parts of the region more accessible. Russia has maintained a substantial military presence there, while China has sought a greater economic and strategic role.
Greenland's mineral resources are another factor, with the island's deposits of critical minerals attracting international interest amid wider concerns over supply chains. For Washington, a larger military presence in Greenland therefore serves several purposes without requiring formal ownership of the territory.
The new restrictions on foreign military installations and sensitive investment are particularly relevant to US concerns about China and Russia gaining a foothold in the Arctic.
What does the deal mean for Denmark and Greenland?
For Denmark, the agreement provides a framework for closer US military involvement in Greenland while retaining Danish sovereignty over the territory.
That is particularly important because Trump's campaign to acquire Greenland had created tensions inside NATO. Denmark and Greenland had repeatedly rejected the idea that the island could simply be sold or transferred to another country.
Greenland's own political future remains separate from the agreement. The territory has a long-running independence debate, and Greenlanders retain the right to determine their future status.
The agreement has no end date and says it would continue to apply if Greenland becomes independent, provided the territory remains in NATO.
The agreement also reinforces NATO's role in Arctic security. Greenland Prime Minister Jens-Frederik Nielsen has stressed the importance of maintaining a strong NATO presence in the Arctic, while Danish Prime Minister Mette Frederiksen has said the agreement respects Greenland's right to self-determination.
AP reported that the agreement emerged after months of negotiations between Washington, Copenhagen and Nuuk and allows the US to expand its military presence while keeping Greenland under Danish control. The arrangement builds on the existing US-Danish defence framework rather than creating an American military presence from scratch.
For Greenland, the agreement balances its right to self-determination with the security demands of an increasingly contested Arctic.
The agreement moves the dispute away from the question of whether Greenland should become US territory and towards the question of how the US, Denmark and Greenland will manage Arctic security.
Trump does not obtain the annexation he had previously sought. Denmark retains sovereignty over Greenland, while Washington gains greater military access and a larger role in the island's security.
The agreement still needs to pass the relevant parliamentary processes, and its provisions will have to be implemented through decisions on military construction, access and cooperation.
Reuters reported that Danish Foreign Minister Lars Løkke Rasmussen framed the agreement as part of a broader NATO approach to Arctic security. Greenland's leadership has similarly stressed the importance of the alliance's role in the region.
The immediate dispute has therefore shifted from whether the US can acquire Greenland to how Washington, Copenhagen and Nuuk will manage the expanded American military presence and Arctic security. Greenland remains under Danish sovereignty, while the agreement leaves the separate question of its eventual political future unresolved.
