On Wednesday, MSNBC's Joe Scarborough reported that Trump had asked his foreign policy adviser repeatedly why he couldn't use nuclear weapons.

"Several months ago, a foreign policy expert went to advise Mr. Trump. … Trump asked three times, in an hour briefing, 'why can't we use nuclear weapons?'"

Retired U.S. Air Force general and former Director of the National Security Agency Michael Hayden also called Trump "erratic," adding that he doesn't know of anyone in the national security community who is advising Trump.

"But he's inconsistent. And when you're the head of a global super power, inconsistency, unpredictability, those are dangerous things. They frighten your friends and they tempt your enemies. And so, I would be very concerned."

Watch the exchange below:

The Trump campaign denied these reports, saying "there is no truth" to them.