Diplomatic relations between Denmark and the United States of America began in 1783. Both countries are founding members of the Arctic Council, OECD, OSCE, NATO and the United Nations.

History

1776-1826 Diplomatic relations date back to 1783, when Denmark signed a commercial treaty with the United States. In 1792, Denmark recognized the independence of the United States. In 1801, diplomatic relations were established, and an American legation was opened in Denmark. The diplomatic relations have never experienced an interruption, since 1801.

In 1801, Denmark became an ally of France in its war against Great Britain, and the Danish Navy seized American merchant ships. A treaty of commerce was signed in 1826, and Denmark agreed to pay the United States an indemnity of $650,000. Agreements - US and Kingdom of Denmark 1776–1826 YearEventDescriptionPrimary Source Link1783Commercial Treaty NegotiationsDenmark and the United States negotiate an initial commercial treaty framework to regulate growing maritime commerce.N/A1792Official Recognition & Consular RelationsDenmark officially recognizes the independence of the United States on June 9, 1792, granting an exequatur to the first U.S. Consul at Copenhagen.U.S. Consular Records1801Establishment of Diplomatic RelationsContinuous, formal diplomatic ties begin on October 12, 1801, when the Danish Minister Resident to the United States officially presents credentials.U.S. Diplomatic Dispatches1801–1814Napoleonic Maritime FrictionAs a French ally, the Danish Navy seizes several American merchant ships during the Napoleonic Wars, sparking long-running indemnity disputes.N/A1826General Convention of Friendship, Commerce, and NavigationSigned on April 26, 1826, this landmark treaty establishes mutual most-favored-nation status and resolves lingering merchant indemnity claims.8 Stat. 340 (Wikisource) 1826-1914

During the Pierce administration, Pierce noted in a speech:Negotiations are pending with Denmark to discontinue the practice of levying tolls on our vessels and their cargoes passing through the Sound. I do not doubt that we can claim exemption therefrom as a matter of right. It is admitted on all hands that this exaction is sanctioned, not by the general principles of the law of nations, but only by special conventions which most of the commercial nations have entered into with Denmark. The fifth article of our treaty of 1826 with Denmark provides that there shall not be paid on the vessels of the United States and their cargoes when passing through the Sound higher duties than those of the most favored nations. This may be regarded as an implied agreement to submit to the tolls during the continuance of the treaty, and consequently may embarrass the assertion of our right to be released therefrom. There are also other provisions in the treaty which ought to be modified. It was to remain in force for ten years and until one year after either party should give notice to the other of intention to terminate it. I deem it expedient that the contemplated notice should be given to the Government of Denmark.During the American Civil War, Lincoln proposed to purchase the Danish West Indies to better maintain its blockade of the Confederacy. The United States Senate refused to go along, and negotiations continued intermittently for five more decades, but both sides had internal opposition.

World War I

Denmark was neutral in World War I, but suffered a significant disruption in trade, and decided its colonies were a financial burden, especially as the inhabitants were restive. The United States did not want Germany to purchase the islands of Saint Thomas, Saint Croix, and Saint John.Bruce W. Jentleson and Thomas G. Paterson, eds. Encyclopedia of US Foreign Relations. (1997) 2:8. In 1916, Denmark sold their Danish West Indies to the United States, and both countries signed the Treaty of the Danish West Indies. The sale for $25 million deal was finalized on 17 January 1917. On 31 March 1917, the United States took possession of the islands and the territory was renamed the Virgin Islands of the United States.Fogdall, Soren, Danish-American diplomacy, 1776–1920 (1922) Online

World War II

During World War II, in April 1941, the United States worked with Henrik Kauffmann, Denmark's ambassador to Washington, to establish a temporary protectorate over Greenland.Bo Lidegaard, Defiant Diplomacy: Henrik Kauffmann, Denmark, and the United States in World War II and the Cold War, 1939–1958 (Peter Lang, 2003).

1945–present

In 1947, the Danish Legation to the United States was upgraded to embassy status by President Truman.

Rejecting Denmark's long history of neutrality, it joined NATO as a founding member in 1949. Danish troops deployed to Bosnia and Herzegovina as part of the United Nations peacekeeping force were assigned to the American sector, coming under direct American command.Jentleson and Paterson, eds. Encyclopedia of US Foreign Relations. (1997) 2:9.

Denmark was active in Afghanistan from 2001-2021 and Kosovo as well as a leader in the Baltic region. Former Danish Prime Minister Anders Fogh Rasmussen reaffirmed that Denmark would remain engaged in Iraq even as its troop levels declined. Denmark was the only Scandinavian country to approve of the American Invasion of Iraq, and Denmark and the United States consult closely on European political and security matters. Denmark shares US views on the positive ramifications of NATO enlargement. Denmark is an active coalition partner in the war on terrorism, and Danish troops are supporting American-led stabilization efforts in Afghanistan and Iraq. The United States also engages Denmark in a broad cooperative agenda through the Enhanced Partnership in Northern Europe, a US policy structure to strengthen US–Nordic–Baltic policy and program coordination.

Russo-Ukrainian war

Denmark, a member of the European Union, sanctioned Russia after its invasion of Ukraine. In 2023, US President Joe Biden met with Danish Prime Minister Mette Frederiksen at the Oval Office and praised Denmark for "standing up" for Ukraine in war with Russia.

In the following days, Denmark, the United States, the United Kingdom, and the Netherlands released a joint statement on delivering 'high priority' air defence equipment to Ukraine.

Second Donald Trump administration (2025–present)

Donald Trump had expressed a desire to acquire Greenland for the United States in his second term. This was met with opposition from Danish Prime Minister Mette Frederiksen, who stated that "Europe won't be blackmailed" in response to President Trump, who had at that point not ruled out force to acquire Greenland.

The landmark treaty (Long Title: Agreement between the Government of the United States of America and the Government of the Kingdom of Denmark together with the Government of Greenland to Amend and Supplement the Agreement of 27 April 1951 Concerning the Defense of Greenland) was signed on 22 September 2026 under the backdrop of 81st United Nations Conference.

The treaty provides the United States with expedited approvals for security related physical infrastructure, two new defense bases, and embedded cooperation with Greenland authorities. These being above and beyond the concessions granted in the 1951 agreement. 2026 Agreement between the Government of the United States of America and the Government of the Kingdom of Denmark together with the Government of Greenland to Amend and Supplement the Agreement of 27 April 1951 Concerning the Defense of Greenland: Concessions GainedCategoryConcession Gained / Key ProvisionPrimary BeneficiaryStrategic DetailsMilitary Base ExpansionEstablishment of two new military basesNew installations granted at Narsarsuaq (southern Greenland) and Mestersvig (east coast).Modernization of Pituffik Space BaseAuthorization granted to expand and modernize existing infrastructure at the United States' primary active base on the island.Access & Transit RightsFlyover & Landing RightsUS military aircraft gain unrestricted transit and landing rights throughout all of Greenland.Undersea & Maritime RightsUS naval vessels gain comprehensive maritime and undersea operational rights in all Greenlandic territorial waters.Permanent Security ControlSolidifies long-term, permanent control over defense coordination, replacing the baseline framework constraints of the 1951 treaty.Strategic ExclusionNon-NATO Military Prohibition / All PartiesExplicitly bars non-NATO nations from establishing any military base or maintaining a troop presence on the island.Foreign Investment Restrictions / Prohibits non-allied nations and foreign adversaries from investing in Greenland's critical minerals and mining sectors.Sovereignty & IndependenceIndependence Contingency Clause / If Greenland chooses independence in the future, it is legally bound to remain in NATO and seamlessly inherit all treaty rights and obligations.

Greenland

Shortly before the purchase of Alaska from the Russian Empire, United States Secretary of State William H. Seward attempted to buy both Greenland and Iceland from Denmark, but was unsuccessful.

Following World War II, the United States developed a geopolitical interest in Greenland, and in 1946, the United States offered to buy Greenland from Denmark for $100,000,000, but Denmark refused to sell.

Pituffik Space Base - the US Space Force base and early warning radar at Thule, North Star Bay, Greenland (a Danish self-governing territory) - serves as a vital link in western defenses. In August 2004, the Danish and Greenland Home Rule governments gave permission for the early warning radar to be updated in connection with a role in the US ballistic missile defense system. At the same time, agreements were signed to enhance economic, technical, and environmental cooperation between the United States and Greenland.

The United States expressed interest in investing in the resource base of Greenland and in tapping hydrocarbons off the Greenlandic coast.Keil, Kathrin (29 August 2011) "U.S. Interests in Greenland – On a Path Towards Full Independence?", The Arctic InstituteAndrews Kurth LLP, "Oil and Gas in Greenland – Still on Ice?" , Andrewskurth.com. Retrieved on 21 June 2016. In August 2019, US President Donald Trump proposed to buy the country, prompting Greenlandic Prime Minister Kim Kielsen to issue the statement, "Greenland is not for sale and cannot be sold, but Greenland is open for trade and cooperation with other countries—including the United States."

On 10 June 2020, the United States reopened its consulate in Nuuk, Greenland. The first US consulate in Nuuk closed in 1953.

Following his re-election in 2024, Donald Trump posted on Truth Social, prior to taking office, that "For purposes of National Security and Freedom throughout the World, the United States of America feels that the ownership and control of Greenland is an absolute necessity", to which Prime Minister Múte Egede responded in a written comment: "Greenland is ours. We are not for sale and will never be for sale. We must not lose our long struggle for freedom." The US government's insistence on acquiring Greenland has caused diplomatic tensions between the two NATO members. It comes as Denmark is reassessing its relations with the United States. In its 2025 annual report, the Danish Defence Intelligence Service classified the United States as a potential threat to Denmark's and Europe's national security. The report mentions the use of economic weapons, especially tariffs, but also notes that Washington will no longer rule out the possibility of resorting to force, even against one of its partners.

1968 Thule Air Base B-52 crash