The United States and Denmark have announced a security agreement that would expand the American military presence in Greenland. The deal is set to be signed at the United Nations General Assembly next week.

US President Donald Trump announced the agreement on Friday in a post on his Truth Social platform, saying it was reached with representatives of Denmark and Greenland.

"At my direction, we worked with representatives of Denmark and Greenland to guarantee that the US will FOREVER have the complete ability to do what is necessary in Greenland," Trump wrote.

Trump said the deal grants the US "permanent control over security, and all other needs" and comes with "no cost to the United States." He added that plans would begin immediately to build a significant US military presence across suitable locations in Greenland.

The agreement also includes a provision barring US adversaries from establishing military bases or personnel in Greenland, or making what Trump described as "sensitive investments," without express written approval from the United States.

Danish Prime Minister Mette Frederiksen confirmed the deal would be signed at the UN General Assembly next week but noted it still requires parliamentary approval. She said the agreement "strengthens our common security in the Arctic and the North Atlantic area" while also recognising "the sovereignty and territorial integrity of the Kingdom and the right of the Greenlandic people to self-determination."

Frederiksen did not directly address the specifics cited by Trump in his social media post.

US Secretary of State Marco Rubio described the agreement as a "historic deal" and a "huge win for the United States and the American people." "This deal permanently and completely addresses our national security concerns in Greenland," he said.

The announcement follows months of pressure from Trump, who had repeatedly threatened to "take" Greenland, citing its strategic location in the Arctic and its mineral wealth.