U.S., Denmark and Greenland Announce Arctic Pact, but Definitions Differ
The United States has reached an Arctic security pact with Denmark and Greenland, Donald Trump announced on Friday. The 18 September announcement names Danish Prime Minister Mette Frederiksen and Greenland government leader Jens-Frederik Nielsen as the other parties.
The United States and Denmark will formally sign the agreement next week on the sidelines of the United Nations General Assembly in New York City, according to the most recent account The Guardian. Trump described the agreement in a Truth Social post as "very important, historic, and special."
Trump claimed it gives the United States permanent control over security and all other needs in Greenland. He claimed it completely addresses all U.S. concerns about Greenland. He said the United States will immediately begin building a large military presence in the appropriate part of Greenland. He said no U.S. adversary can have a base, have a military presence, or make sensitive investments in Greenland without U.S. express written approval. In plain terms, he described a U.S. veto, like a gatekeeper who must say yes before rivals can operate or invest.
That language differs from Copenhagen and Nuuk. Frederiksen said the agreement recognizes the sovereignty and territorial integrity of the Kingdom, meaning Denmark's legal borders and authority stay intact, and the right of the Greenlandic people to self-determination, meaning Greenlanders decide their own political future. Nielsen said the agreement ensures and strengthens the security of Greenland, the Kingdom of Denmark, the United States and the Western alliance Danish Prime Minister's Office.
The pact will need to go through parliamentary procedures to be enacted. That means lawmakers in Denmark and Greenland must still review and approve it.
The announcement follows months in which Trump threatened to take Greenland by force. At a NATO summit in Ankara earlier this year, NATO is the U.S.-European military alliance, Trump renewed his bid for the United States to acquire Greenland. He threatened to pull all American armed forces out of Europe after pushback over Greenland.
Denmark moved to bolster its Arctic presence after U.S. demands to acquire Greenland. Denmark deployed conscripts to Greenland for the first time in recent history Reuters. On Sept. 14, Frederiksen said she hoped for a peaceful way forward with the United States on Arctic and Greenland Reuters.
The legal baseline is not new. Greenland is a self-governing territory of the Kingdom of Denmark. Denmark is a NATO member. The United States already has a presence in Greenland and the right to expand bases through NATO. A Danish Prime Minister's Office press-meeting record of 3 April 2025 states that Greenland is part of NATO and that a 75-year defense agreement gives wide access to Greenland. A Joint Statement hosted by the same office states that security in the Arctic must be achieved collectively in conjunction with NATO allies including the United States. The leaders of Denmark and Greenland stated that Greenland's sovereignty is non-negotiable.
The broader context here is a negotiation told in two vocabularies. Washington is presenting the outcome as permanent U.S. control over security requirements and a veto over adversary basing and sensitive investment. Copenhagen and Nuuk are presenting the same outcome as collective security within existing sovereignty, territorial integrity and self-determination.
Looking ahead for practitioners, three ambiguities will decide the substance. The first is basing authority. Permanent control, expanded presence, and pre-existing rights to expand bases through NATO are distinct legal propositions. The text to be signed in New York will need to reconcile them. The second is investment screening, the system for reviewing and blocking risky foreign money. Express written approval for adversary activity implies a referral and clearance mechanism. Its scope, thresholds and administering authority are not yet public. The third is ratification, the formal approval by lawmakers. Parliamentary procedures in Denmark and Greenland provide a second venue where sovereignty assurances and U.S. prerogatives will be tested against domestic law.
In my view, the shift from acquisition by force to a signed framework does not resolve the underlying tension over jurisdiction in the North Atlantic. It channels it into treaty language, legislative review and alliance consultation. Watch the signature text, not the announcement.
