U.S. President-elect Donald Trump stands with retired Marine Gen. JamesMattis following their meeting at the main clubhouse at Trump National Golf Club in Bedminster, New Jersey, U.S., Nov. 19, 2016. (REUTERS/Mike Segar)

WASHINGTON, Dec. 1 (Xinhua) --- U.S. President-elect Donald Trump said on Thursday he has chosen retired Marine General James Mattis for secretary of defense.

"We are going to appoint 'Mad Dog' Mattis as our secretary of defense. But we're not announcing it until Monday so don't tell anybody," Trump said at a rally in Cincinnati, kicking off his post-election "Thank You" tour.

"They say he's the closest thing to Gen. George Patton that we have and it's about time." he added.

Mattis emerged as the top contender for Pentagon chief soon after Trump won the White House. The two men met in New Jersey on Nov. 19, with media reporting that Trump was impressed by Mattis' resume.

U.S. media speculated that an extensive knowledge about the Middle East and a tough stance against extremism helped Mattis get the job.

Since the U.S. law prohibits military officers from becoming defense secretary within seven years of retirement, Mattis must acquire a special waiver from the Congress to become eligible.

The waiver has only been given once before.

Mattis, 66, enlisted in the military in 1969, was promoted through the ranks for his performances in the first and second gulf wars and the Afghanistan War.

Known as "Mad Dog" and "Warrior Monk," he retired as chief of U.S. Central Command in 2013. He has often criticized Washington for lacking an overall strategy in the Middle East.