US Defence Secretary Donald Rumsfeld says America expects "to get" Osama bin Laden.
His comments come after he was reported saying that US forces may never be able to catch him.
At a Pentagon briefing, he was questioned repeatedly about an interview with USA Today, in which he was quoted as saying the US might not catch bin Laden.
Rumsfeld repeated his comments that the effort to find the terrorist leader could be a long and arduous one, and that the military's role is just a portion of it.
He said: "Until you have him, you do not have him, so what is progress? Until he is no longer functioning as a terrorist, he is functioning as a terrorist, there isn't any progress - you either have him or you don't.
"Are we continuing the effort? You bet. Do we expect to get him? Yes."
In the USA Today interview, Rumsfeld was quoted as saying it will be "very difficult" to capture or kill bin Laden.
He says: "It's a big world. There are lots of countries. He's got a lot of money, he's got a lot of people who support him and I just don't know whether we'll be successful. Clearly, it would be highly desirable to find him."
Meanwhile, General Richard Myers, the chairman of the Joint Chiefs of Staff, said the previous day's bombing campaign attacked nine targets with 80 strike aircraft, and was directed at "degrading Taliban forces".
He said: "This is proceeding according to our plan. ... We don't feel this is piecemeal, we feel this is very deliberate, very well planned. Success is yet to be determined but we think we are having some success," Myers said.