Washington (CNN) President Donald Trump said in an interview segment released Sunday that he was unsure how long Defense Secretary James Mattis planned to stay in his administration.

"Well, I don't know," Trump said when asked whether the Pentagon chief would be leaving in an interview on CBS's "60 Minutes." "He hasn't told me that."

Trump said the two maintained "a very good relationship," but he allowed for the possibility Mattis would leave.

"I think he's sort of a Democrat, if you want to know the truth," Trump said in the interview slated to air Sunday night. "But General Mattis is a good guy. We get along very well. He may leave. I mean, at some point, everybody leaves. Everybody. People leave. That's Washington."

Army Col. Robert Manning, a spokesman for the Pentagon, issued a statement in response to the President's remarks.

Read More