US President Donald Trump, Danish Prime Minister Mette Frederiksen, and Greenland Prime Minister Jens-Frederik Nielsen signed a landmark trilateral defence agreement on 23 September 2026 at the United Nations, modernising a foundational 1951 security pact and significantly expanding cooperation in the strategically vital Arctic region. The signing marks a pivotal moment in the geopolitics of the High North, where great-power competition has intensified sharply in recent years.

What the New Agreement Covers

The updated pact replaces and substantially expands the framework established by the original 1951 defence agreement between Washington and Copenhagen, which was last amended in 2004. The new deal is designed to reinforce security and deterrence in the Arctic and the North Atlantic, while explicitly ensuring that Greenland is a direct participant — rather than merely a subject — in decisions affecting its territory and people.

Speaking at the trilateral ceremony, Trump described the agreement as the outcome of a prolonged diplomatic effort. 'We're going to have a tremendous relationship, a secure relationship, and we look forward to it,' he said. 'This was long in the making. Some really wanted to make a deal and never got done, but we're getting it done.' Trump added the pact would be 'tremendous for Europe and for the United States and for everybody,' and 'incredible' for Greenland.

Frederiksen: A Deal 'That Can Last Forever'

Frederiksen called the agreement a milestone in Denmark's decades-long security relationship with the United States. '75 years ago, we entered into an agreement about the defense of Greenland. Today, we are signing an even bigger and better agreement, a deal that can last forever,' she said.

The Danish prime minister said the pact would prevent adversaries from gaining a foothold in Greenland. 'We are making sure that they will not be allowed to get any control or significant influence in Greenland,' she said, adding that 'more allies are present in the Arctic at the same time.' Frederiksen also framed the deal as a pillar of broader NATO cohesion at a time of heightened geopolitical tension. 'If we let ourselves be divided as allies, then we do our foes a favor,' she warned.

Nielsen: 'An Agreement With Us, Not Just About Us'

Greenland Prime Minister Jens-Frederik Nielsen said the agreement brought the 1951 pact 'into 2026' and, crucially, ensured Greenland's direct agency. 'For Greenland, this is not only an agreement about us, it is an agreement with us,' he said. 'It takes into account the people of Greenland, our rights, our livelihoods, and the development of our country.'

Nielsen recalled Greenland's security contributions during the Second World War and the Cold War, and affirmed its commitment to the Western alliance. 'This agreement should put to rest any doubt today and in the future about where Greenland's loyalty lies. We are, have been and will remain a steadfast friend of the United States and a part of the Western Alliance,' he said, describing the deal as a 'win-win-win agreement' grounded in shared responsibility and mutual respect.

Trump Sidesteps Ownership Question

Notably, Trump declined to directly answer a reporter's question on whether US ownership of Greenland was now off the table — a proposition he has publicly floated on multiple occasions. When asked what message he had for the people of Greenland, Trump replied: 'I love the people of Greenland,' adding that they were 'very well represented by their prime minister.' The non-answer is likely to sustain questions about Washington's longer-term ambitions in the region.

Arctic Stakes and What Comes Next

This comes amid a broader intensification of Arctic competition, with Russia and China each expanding military and commercial activity in the High North. Greenland's geographic position — straddling key transatlantic shipping lanes and sitting atop significant rare-earth mineral deposits — makes it one of the most strategically coveted territories on earth. The updated defence pact reinforces the US military presence at facilities including Pituffik Space Base (formerly Thule Air Base), which anchors American missile-warning and space-surveillance capabilities. How the agreement translates into concrete force posture changes and joint investment commitments will be closely watched in the months ahead.