The US, Denmark and Greenland have reached an agreement to significantly expand the US military presence on the strategically located Arctic island, with US President Donald Trump saying Washington would “immediately” begin developing a large military presence there.Trump announced the agreement on Friday in a post on Truth Social, saying it gives the US “permanent control over security” in Greenland and the ability to take necessary measures to protect the island and the US.“We will immediately begin the process of developing a large Military presence in the appropriate part of Greenland,” Trump said.The agreement, however, falls short of Trump’s earlier demand for US acquisition of Greenland. Reuters reported that the deal would expand the US military footprint while keeping the island under Danish sovereignty.Strategically positioned between North America and Europe and close to Russia, Greenland has gained increasing importance as melting Arctic ice opens new sea routes and intensifies competition over security and resources.The US already maintains a military presence there through Pituffik Space Base in northwestern Greenland. The base supports missile warning, missile defence and space surveillance operations and traces its origins to the Cold War-era US military presence on the island.During the Cold War, the US established several military installations in Greenland. The US Army operated missile batteries for air defence, while the Ballistic Missile Early Warning System and Satellite Control Network were also established there.Trump’s latest announcement follows months of tensions over his calls for US control of Greenland. During his second term, which began in January 2025, he repeatedly argued that the island was essential to US national security and had refused to rule out the use of force to acquire it. Denmark and Greenland had rejected the idea.On Friday, Trump said the agreement would ensure that no US adversary could establish a base, maintain a military presence or make sensitive investments in Greenland without Washington’s approval.Danish Prime Minister Mette Frederiksen and Greenland’s Prime Minister Jens-Frederik Nielsen welcomed the agreement while stressing that Greenland’s sovereignty would remain intact.Frederiksen said the agreement recognises “the sovereignty and territorial integrity of the Kingdom and the Greenlandic people’s right to self-determination”. Nielsen said the deal strengthens the security of Greenland, Denmark, the US and the Western alliance.The agreement is expected to be formally signed on the sidelines of the United Nations General Assembly in New York next week. Its precise implementation, including whether and where new US bases will be built, remains unclear.The US already has broad basing and overflight rights in Greenland under a 1951 defence treaty with Denmark, which was updated in 2004. The new agreement would further expand the US military role on the island and seek to prevent rival powers from establishing a strategic foothold there.