President Donald Trump signed a security agreement with Denmark and Greenland aimed at strengthening Arctic and North Atlantic security and expanding the U.S. military presence in Greenland.

The agreement keeps Greenland under Danish control and would remain in effect if the territory eventually becomes independent, as long as it remains in NATO.

The deal allows the United States to expand and modernize military activities at the existing Pituffik Space Base and develop additional defense areas in Greenland.

The agreement follows years of tension after Trump repeatedly expressed interest in acquiring Greenland and, during his second term, threatened to take the territory from Denmark, the AP has reported.

Officials from the United States, Denmark and Greenland negotiated the agreement for months, with the deal addressing U.S. security concerns while maintaining Greenland’s and Denmark’s sovereignty.