US and Denmark sign Arctic security deal with Greenland, ending months of tension

On September 22, 2026, the United States, Denmark, and Greenland signed a landmark trilateral security agreement in New York, ending months of diplomatic tension triggered by U.S. President Donald Trump's threats to acquire the mineral-rich Arctic island. The deal allows the U.S. to establish two new military bases at Narsarsuaq and Mestersvig, expand its Pituffik Space Base, and deploy a 'Golden Dome' missile defense system, while explicitly barring non-NATO military installations and protecting Greenland's right to self-determination.

Trilateral Arctic security agreement

• ▪The trilateral Arctic security agreement signed by the United States, Denmark, and Greenland on September 22, 2026, has no end date and can only be amended by mutual consent of the United States, Denmark, and Greenland
• ▪The trilateral security agreement signed by the United States, Denmark, and Greenland on September 22, 2026, amends a 1951 defense treaty governing Greenland's defense between the United States and Denmark
• ▪The trilateral Arctic security agreement signed by the United States, Denmark, and Greenland on September 22, 2026, must be approved by the parliaments of Greenland and Denmark before it officially goes into effect
• ▪On September 22, 2026, U.S. President Donald Trump, Danish Prime Minister Mette Frederiksen, and Greenland Prime Minister Jens-Frederik Nielsen signed a trilateral security agreement on the sidelines of the UN General Assembly in New York

Trump's territorial acquisition threats

• ▪U.S. President Donald Trump did not respond to questions on September 22, 2026, about whether a U.S. acquisition of Greenland was off the table
• ▪U.S. President Donald Trump previously threatened to acquire Greenland from Denmark, causing diplomatic tensions within NATO and concerns among Greenland's population
• ▪Danish Prime Minister Mette Frederiksen warned that a U.S. takeover of Greenland would lead to the end of the Atlantic alliance

New US military bases

• ▪The trilateral security agreement signed by the United States, Denmark, and Greenland in New York on September 22, 2026, allows the United States to establish two new military bases in Greenland, located at Narsarsuaq in the south and Mestersvig on the east coast
• ▪The security agreement signed by the United States, Denmark, and Greenland on September 22, 2026, requires the United States to award contracts for goods and services related to setting up, maintaining, or dismantling the new military bases at Narsarsuaq and Mestersvig to Greenlandic sources to the maximum extent possible
• ▪The Arctic security agreement signed by the United States, Denmark, and Greenland on September 22, 2026, allows the United States to modernize and expand its activities at the Pituffik Space Base in northwestern Greenland

Expanded US military presence

• ▪The Arctic security agreement signed by the United States, Denmark, and Greenland on September 22, 2026, bars non-NATO countries from establishing a persistent military presence or manned or unmanned military installations in Greenland
• ▪The Arctic security agreement signed by the United States, Denmark, and Greenland on September 22, 2026, bars investors from outside NATO member states, NATO partners, or the European Union from gaining control or major influence over sensitive sectors in Greenland
• ▪The security agreement signed by the United States, Denmark, and Greenland on September 22, 2026, grants U.S. military aircraft and vessels flyover, landing, and undersea access rights throughout Greenland and its territorial waters
• ▪The Arctic security agreement signed by the United States, Denmark, and Greenland on September 22, 2026, permits the United States to establish a 'Golden Dome' missile defense system in Greenland to shield against ballistic missile threats

NATO Arctic security framework

• ▪Under the Arctic security agreement signed by the United States, Denmark, and Greenland on September 22, 2026, if Greenland chooses to become independent, it must remain in NATO and assume Denmark's rights and obligations under the pact
• ▪NATO Secretary-General Mark Rutte and European Council President Antonio Costa welcomed the Arctic security agreement signed by the United States, Denmark, and Greenland on September 22, 2026, as a positive step for transatlantic cooperation and Arctic security

Greenland self-determination rights

• ▪The Arctic security agreement signed by the United States, Denmark, and Greenland on September 22, 2026, explicitly states that it respects Greenland's right to self-determination and requires the United States to respect Greenlandic society and the Greenlandic way of life
• ▪Greenland lawmaker Naaja Nathanielsen described the security agreement signed by the United States, Denmark, and Greenland on September 22, 2026, as a huge step forward in Greenland's quest for self-autonomy and a larger seat at the table

Debatable claims

• ▪The security pact's NATO requirement undermines Greenland's future sovereignty
• ▪Greenland's parliament should reject the trilateral security agreement
• ▪Expanding the US military presence in Greenland destabilizes the Arctic