According to a White House statement, the agreement guarantees the United States the ability to defend the North American continent, includes permanent basing rights and bars any US adversary from establishing a military base, military presence or sensitive investment in Greenland without Washington's approval.

Speaking at the signing ceremony, Trump said: "This agreement gives the United States permanent control over security and all other needs on that territory."

"We will have the complete ability to do what is necessary to defend the American continent," he said.

Danish Prime Minister Mette Frederiksen described the agreement as a "milestone".

"75 years ago, we entered into an agreement about the defense of Greenland. Today, we are signing an even bigger and better agreement — a deal that can last forever," she said.

"This deal is good for the United States, it's good for Greenland, for Denmark, for the NATO alliance, and therefore, also good for Europe. In other words, we are strengthening our common security, boosting our common deterrence, showing our adversaries who we are — and we are doing it together," Frederiksen said.

Greenland Prime Minister Jens-Frederik Nielsen said Greenland would remain a "steadfast friend" of the United States and part of the Western alliance.

"Your security is our security and our security is your security. We are truly pleased with the result that strengthens our shared security and strengthens our bond as close allies. This agreement is historical," he said.

The agreement expands the US military presence and access in Greenland while leaving the territory under Danish sovereignty. Reporting on the deal says it also provides for expanded basing rights and seeks to prevent non-NATO adversaries from establishing a military or strategic presence there.

The announcement comes after months of diplomatic tensions triggered by Trump's repeated calls for greater US control over Greenland, including previous suggestions that Washington could acquire the territory and, at one point, use force.

The United States already operates the Pituffik Space Base in northern Greenland. The new agreement is intended to strengthen US and NATO security arrangements in the strategically important Arctic region.