President Trump has issued a direct rebuke of NATO partners on social media, signaling that the United States may withdraw from the alliance.

In a Truth Social post Wednesday evening, Trump wrote in all caps: “NATO WASN’T THERE WHEN WE NEEDED THEM.” He added: “And they won’t be there when we need them again,” and concluded with: “Remember Greenland.”

The remarks follow the White House’s indication that the United States may withdraw from NATO. A White House press secretary, Karoline Leavitt, previously quoted Trump to reporters stating: “They were tested, and they failed.” She also noted it was “quite sad that NATO turned their backs on the American people over the course of the last six weeks when it’s the American people who have been funding their defense.”

Trump has repeatedly threatened to withdraw from NATO and criticized European nations for restricting access to U.S. military bases and providing limited support during Operation Epic Fury, an offensive against Iran. In a March 31 post on Truth Social, Trump described NATO as a “one-way street,” saying: “You’ll have to start learning how to fight for yourself, the U.S.A. won’t be there to help you anymore, just like you weren’t there for us.”