The White House said the United States is considering “a range of options” to acquire Greenland, including possible military measures, calling control of the Arctic island a national security priority.

Greenland, a semi-autonomous territory of Denmark, is a fellow NATO member. The announcement came hours after European leaders issued a joint statement supporting Denmark in response to President Donald Trump’s expressed interest in the island.

Over the weekend, Trump reiterated that the US “needed” Greenland for security purposes. Danish Prime Minister Mette Frederiksen warned that any US attack would constitute a major breach of NATO commitments.