Trump says US air support possible for Ukraine security guarantee

"When it comes to security, they're willing to put people on the ground," he told Fox News, referring to European allies whom he met in the White House on Monday.

"We're willing to help them with things, especially, probably, if you talk about by air, because no one has the kind of stuff we have, really, they don't," Trump said.

He added his "assurance" that no US ground troops would deploy to Ukraine, and he categorically ruled out Ukraine joining the Western military alliance NATO.