The United States, Denmark and its autonomous territory of Greenland on Tuesday signed an agreement in New York to expand the US military presence on the strategically located Arctic Island, easing months of tensions within the NATO alliance over US President Donald Trump's push to acquire Greenland.

Trump, Danish Prime Minister Mette Frederiksen and Greenland's Prime Minister Jens-Frederik Nielsen signed the agreement on the sidelines of the UN General Assembly.

Nielsen told Greenlandic broadcaster KNR that it would take time to rebuild trust between Greenland and the United States after months of tensions.

Besides allowing the US to modernize and expand activities at Pituffik Space Base and establish additional defense areas at Narsarsuaq and Mestersvig, the agreement also contains provisions that extend beyond military affairs, including restrictions on certain foreign economic activities in Greenland's sensitive sectors.

Beyond military affairs

The agreement's emphasis on the US defense presence in Greenland is accompanied by provisions that can also affect the island's economic choices, particularly in the juncture of economic affairs and military concern.

The rationale for these economic provisions is not explicitly attributed to the United States in the text. But Trump has repeatedly framed Greenland's security in broader terms.

In a Truth Social post announcing the agreement, Trump said it gives the United States "permanent control" over Greenland's security and addresses "ALL of our many US concerns." He also described it as an "Infinite Life" agreement.

Article X is particularly notable. It says the parties recognize a threat to national security and public order from efforts by "adversaries" to "expand influence and control" in Greenland. It then establishes restrictions on investment and access in sensitive sectors involving states or investors outside NATO, NATO partners and the EU.

The agreement says Greenland will apply its current or future investment-screening laws "in close cooperation" with Danish authorities, while relevant Danish authorities will engage in "close consultation" with US authorities and other partners.

It also defines "particularly sensitive sectors or activities" to include critical infrastructure and "the extraction of resources." This gives the provisions a direct potential impact on Greenland's mining sector, including its rare-earth resources.

Critical minerals come into focus

Greenland has attracted international attention for its deposits of rare earth elements and other critical minerals. The Center for Strategic and International Studies, a research organization based in Washington, DC, identifies the Tanbreez and Kvanefjeld deposits as two of the island's major rare-earth projects. Greenland's own 2025 mineral resources strategy also lists several areas with rare-earth potential.

The US interest is not new. Reuters reported in January 2025 that US and Danish officials had urged the developer of Tanbreez not to sell the project to Chinese-linked buyers. The deposit was subsequently sold to New York-based Critical Metals Corp.

Washington's interest has since extended to potential financial support. Reuters reported that the US Export-Import Bank issued a letter of interest for a loan of up to $120 million for the Tanbreez project, while US officials have also discussed a possible government stake in the company developing it.

The strategic importance of rare earths also extends beyond Greenland. The US Geological Survey's 2025 list of critical minerals includes 15 rare-earth elements, while the European Commission identifies rare earths as critical because of their economic importance and supply-chain risks.

The new agreement, by placing resource extraction within its particularly sensitive sectors and creating a formal investment-screening and consultation framework, could affect the conditions under which foreign investors participate in the development of such resources.

In that sense, the agreement is broader than a conventional arrangement governing military bases. It links economic activity in sensitive sectors to a wider security framework, giving Washington a formal role in consultations and potentially the ability to influence or block certain investments, while creating a more favorable position for US firms in those sectors.

No end date

The agreement also seeks to preserve the arrangement through any future change in Greenland's constitutional status.

Article XI states that the agreement has no end date and may only be amended by mutual consent. If Greenland exercises its right to self-determination and becomes independent, Denmark and Greenland are to work together to ensure that the new state remains in NATO and "affirmatively assumes" the rights and obligations Denmark holds under the agreement.

Trump described it as an "'Infinite Life' Agreement" and said there would be "no cost" to the United States, although the agreement does not itself explain that claim in relation to the planned expansion and refurbishment of US facilities.

The reaction among Greenlanders has been more cautious. Before the agreement was signed, the media outlet in Greenland Sermitsiaq interviewed residents in Nuuk and Ilulissat who said they wanted to see the text and understand how it would affect Greenland's future and everyday life.

The agreement was signed in New York a day before Trump addressed the UN General Assembly during its high-level week, when world leaders gathered to present their views on international affairs.

In his address, Trump devoted substantial time to describing what he portrayed as diplomatic and military achievements, including the war in Gaza, US military action against Iran, and the new agreement with Denmark and Greenland. He presented the Greenland deal as an "unprecedented agreement" concerning the defense of North America.