U.S. Defense Secretary Robert Gates confirmed on Monday that he would quit the job next year.

In this Aug 9, 2010 file photo, Defense Secretary Robert Gates takes part in a news conference at the Pentagon. Gates says he plans to leave his job next year. [Chinadaily.com.cn via Agencies]

In an interview published by Foreign Policy magazine, Gates said by 2011, they will know if the strategy the administration is implementing is working in Afghanistan, and "it seems like somewhere there in 2011 is a logical opportunity to hand off."

"This is not the kind of job you want to fill in the spring of an election year," Gates said, noting that it would be "a mistake to wait until January 2012," when the election year starts, as the administration "might have trouble getting the kind of person they want if there's a possibility that they might only be in the job for a year."

"Who knows what the election situation will look like," Gates said, noting that's why he thinks "sometime in 2011 sounds pretty good" for leaving his job.

"I think the toughest thing in public life is knowing when to dance off the stage. And to leave when people say, 'I wish you weren't leaving so soon,' instead of 'How the hell do we get that guy out of there?'" Gates said, noting managing "two separate wars for every day I've been on the job is very wearing."

"There's a certain point at which you just run out of energy."

Gates, the 22nd secretary of defense, also said if he stay until January of 2011, he will have been in the job longer than all but four of his predecessors. Those four are Robert McNamara, Donald Rumsfeld, Cap Weinberger, and Charles Wilson.

The interview was conducted on July 12 in Gates' office at the Pentagon. In the interview, Gates also discussed the Afghan strategy, and his initiative to cut defense spending.

He said if there are no concrete signs of progress with the recent U.S. troop surge in Afghanistan, then he will recommend a change of course for Obama's year-end Afghan strategy review.

"We're just not going to plunge ahead with exactly the same strategy if it's clear it's not working."