“I think NATO is an important strategic alliance, and I don’t want to see any sacrifice of NATO whatsoever,” said Rep. Brian Mast, chair of the House Foreign Affairs Committee. “They’re important allies, and we want to see that to continue.”

But while Mast, a close Trump ally, said the U.S. and its European allies were having a “hard conversation” that he expected would ultimately bring the longtime allies closer, he did not rule out the Trump administration using military force to take over Greenland, provided it was legally within Trump’s constitutional powers.

“I’m willing to accept any action that takes place based upon the authorities that the administration has,” Mast said. “There’s not going to be any option that’s taken off the table.”

Under the Constitution, Congress has the power to declare war and the duty to fund the military, while the president serves as head of the armed forces.