Secretary of Defense Jim Mattis was caught making a funny remark to newly appointed national security advisor John Bolton while meeting him for the first time on Thursday.

"I heard you're actually the devil incarnate and I wanted to meet you," Mattis said jokingly while walking up the steps of the Pentagon. Bolton responded by laughing.

Mattis is well known for his quick and witty remarks. In an interview on CBS "Face The Nation," host John Dickerson asked, "What keeps you awake at night?" Mattis responded almost immediately and in a blunt tone "nothing. I keep other people awake at night."

It was reported earlier this week that Mattis was not sure if he would be able to work with the new national security advisor due to Bolton's hawkish views. But he denied the reports, saying he had "no reservations, no concerns at all" with Bolton.

See the interaction here: