U.S. President Donald Trump floated the idea that Spain could be removed from NATO as he met with Finnish President Alexander Stubb on Thursday, in his latest swipe against a chronic under-spender on defense.

"Spain — you have to call them and find, why are they a laggard?” Trump said as he spoke with Stubb in the Oval Office. "And they’re doing well too, you know. Because of a lot of the things we’ve done, they’re doing fine. They have no excuse not to do this. But that’s all right.”

"Maybe you should throw them out of NATO, frankly,” he added.