President Barack Obama praised the former Defense Secretary who had some scathing criticisms of his administration -- and said he's still got faith in the US mission in Afghanistan.
Speaking in the Oval Office, Obama said former Defense Secretary Bob Gates "was an outstanding secretary of defense, a good friend of mine, and I'll always be grateful for his service."
Obama's remarks come as Gates' memoir hits the shelves on Tuesday. In it, he accuses Obama of expressing doubts about the U.S. mission in Afghanistan.
Obama told reporters "war is never easy" and that one was "constantly asking" how the strategy could be improved.
"What's important is that we got the policy right, but this is hard, and it always has been," Obama told reporters. "Whenever you've got men and women that you're sending into harm's way, after having already made enormous investments of blood and treasure in another country, then part of your job as commander in chief is to sweat the details on it."
Obama said he has faith in the mission, and that "most importantly I've had unwavering confidence in our troops, in their performance in some of the most difficult situations ..."
He added, "That job is not yet done. And I do think it's important for Americans to recognize that we still have young men and women in harm's way along with coalition partners who are continuing to make sacrifices and we need to see this job all the way through."
Some lawmakers have criticized Gates for publishing the book while Obama is still in office, but Obama dodged a question from reporters on whether he was "irked" that the book had come out while troops were still in the country.