President Donald Trump said on Friday that the US has struck an agreement with Denmark and Greenland that gives Washington "permanent control" over the island's security.
He said in his post on Truth Social that there would be "no cost" to US taxpayers, describing the "infinite life agreement" as "very important, historic and special".
"At my direction, we worked with representatives of Denmark and Greenland to guarantee that the United States will forever have the complete ability to do what is necessary in Greenland in order to secure and defend the security of Greenland, and the United States of America," he wrote.
Mr Trump said the agreement meant "no US adversary can ever have a base in Greenland, have a military presence in Greenland, or make sensitive investments in Greenland, without our express written approval".
The Danish government said in a statement that the US and Denmark would formally sign the agreement on the sidelines of the UN General Assembly next week.
"It is gratifying that we are about to enter into an agreement that ensures and strengthens the security of Greenland, the kingdom of Denmark, the United States and the western alliance," said Jens-Frederik Nielsen, head of the Greenland government. "The agreement recognises Greenland's interests and our place in international co-operation. It is for the benefit of us all."
Once signed, the agreement will need to go through parliamentary procedures to be enacted, the statement said.
"For over 100 years, presidents have known the strategic importance of Greenland, but none of them were able to do anything about it," Mr Trump added in the post. "I am proud to be the president that permanently and conclusively addressed this very important situation."
Mr Trump said the US would "immediately" begin the development of a large military presence in Greenland.
Since his return to office last year, he has expressed a desire for the US to take over Greenland, speaking of its importance to US national security, as well as its wealth of natural resources.
His threats to take over Greenland drew criticism from European allies. In January, he said he would not rule out military action to acquire the island of 57,000 people.
