Trump Says He'll 'Appoint' Gen. James 'Mad Dog' Mattis as Defense Secretary

Trump made the announcement at a rally in Cincinnati, Ohio.

"We are going to appoint 'Mad Dog' Mattis as our Secretary of Defense," Trump said in Cincinnati, Ohio. "But we're not announcing it till Monday so don't tell anybody. Mad dog. He's great. He is great."

The 66-year-old earned his nicknames 'Mad Dog' and the 'Warrior Monk' for his attention to military tactics and strategy. He is known for his candor and blunt talk, which have at times gotten him into hot water.

Mattis emerged as a frontrunner for defense secretary after Trump met with him at his estate in Bedminster, NJ.

The president-elect soon after tweeted, calling Mattis "very impressive."

In addition to being confirmed by the U.S. Senate, Mattis would also need a special waiver from Congress due a statute that bars members of the armed services from entering government positions intended for civilians until seven years after their retirement.