The US, Denmark and Greenland have signed a defence deal that allows Washington to build two new military bases in the Arctic territory, while reaffirming Copenhagen's sovereignty over it.
At a signing ceremony at the UN General Assembly in New York, US President Donald Trump said "we will immediately begin the process of developing a large military presence in the appropriate locations".
Danish PM Mette Frederiksen said the deal was "good for the US, Denmark and Greenland" and also for Europe and Nato, while Greenland's PM Jens-Frederik Nielsen said it was a "win-win-win".
The three leaders then inked the deal, seemingly ending more than a year of tension over the Arctic territory.
Trump had threatened to "take" the semi-autonomous Arctic territory over what he said were national security concerns, citing its strategic defence location and its mineral wealth.
His rhetoric prompted outcry from Greenlanders, Danes and European leaders who issued a joint statement saying his words "undermine transatlantic relations and risk a dangerous downward spiral".
The deal signed on Tuesday amends and updates a 1951 defence agreement between Denmark and the US.
The new agreement says the US "shall be allowed to establish an additional Defence Area at Narsarsuaq and Mestersvig" - referring to locations in Greenland's south and east.
Narsarsuaq has deep-water access and a large runway which US military engineers were surveying last week, according to Danish media.
The Mestersvig outpost is remote, far less developed, and used by a Danish naval dog sled unit.
The "modalities and technical details" of the bases are yet to be confirmed, and according to the deal, must be mutually agreed by all parties.
Washington currently operates its Pituffik Space Base in Greenland's north-west, and the new deal allows the US to "modernise and expand its activities" there.
It also says that "no state that is not a member of Nato shall be allowed to establish its own manned or unmanned military installations in Greenland nor shall they be allowed a persistent presence of military forces in Greenland".
Speaking at the signing ceremony, Trump said: "We going to have a tremendous relationship, a secure relationship."
"This is tremendous for Europe and for the United States, for everybody, and for Greenland it's going to be incredible."
Meanwhile, Frederiksen described the signing of the deal as a "milestone in our long-standing co-operation".
"Seventy-five years ago we entered into an agreement about the defence of Greenland. Today, we're signing an even bigger and better agreement - a deal that can last forever."
The Danish prime minister stressed that the agreement "respects sovereignty and territorial integrity of the Kingdom of Denmark, as well as Greenland's right to self-determination".
Jens-Frederik Nielsen said that "for Greenland, it is not only an agreement about us, it is [an] agreement with us.
"It takes into account the people of Greenland, our rights, our livelihoods and the development of our country.
"Greenland matters for North American security and for transatlantic security," he said, adding that the Nato had a key role to play in the North Atlantic in a changing security situation.
The agreement also confirmed Greenland would remain in Nato if it were to gain independence from Denmark.
The 1951 agreement already allowed the US to send as many troops as it wanted to Greenland. Washington already has more than 100 military personnel permanently stationed at its Pituffik base.
Trump had tried for months to purchase or annex Greenland, arguing that it was vulnerable to adversaries, including Russia and China.
He argued the Arctic island was an essential piece of his plan to build a futuristic "Golden Dome" defence system to protect the US against missile attacks.
However the deal only mentions the project once, and contains no concrete proposal.
The island has vast - and largely untapped - reserves of rare earth minerals, many of which are crucial for technologies including mobile phones and electric vehicles.
Trump said last week that the new deal came with "no cost to the United States".
A Nato spokesperson said shortly afterwards that the military alliance welcomed the deal, which would "help advance security, stability and cooperation in this vital region".
