March 23, 2008 -- Sen. Chuck Hagel, R - Neb., said this morning he is not ready to endorse Sen. John McCain, R - Ariz., for president.

"I think endorsements, at least when I endorse someone, or when I work for someone, or commit to someone, I want to be behind that person in every way I can," Hagel said in an exclusive "This Week" interview.

Hagel pointed to their differing views over foreign policy in explaining his hesitation. "I've obviously got some differences with John on the Iraq war. That's no secret. I want to understand a little more about foreign policy, where he'd want to go. Certainly doesn't put me in Obama or Clinton's camp. But John and I have some pretty fundamental disagreements on the future of foreign policy," he said.

The Foreign Relations Committee member also fielded questions on his view of the troop surge in light of McCain's strong support of the troop increase. Hagel defended himself against suggestions that he had opposed the troop surge.

"That's not what I said. I said, what you will do is, you will further bog yourselves down into a situation, making the Iraqis more dependent on you, making it more difficult to get out. In the end, you're not going to be any closer to a political reconciliation," he explained.

Hagel decline to comment when asked if he agreed with the timetables for troop withdrawal put forth by the Democratic candidates, but did note that "we need a clear plan, and yes, withdrawal. We're going to have to start working our way out of this. How we do it must be responsibly. We're in a deep hole. I think we're in a quagmire. But at the same time, we have national interests there. We have allies there."

He went on to admit that "I haven't really looked at their plans ... I don't know what their plans are. I know what they've said, that they want to bring troops out of there. I know that. I've never seen the specifics of how they want to do that responsibly, the timeline, as I know we've debated general timelines in the Congress. I've never looked at it."

On his political future, Hagel responded to rumors that he would be a possible Secretary of Defense in an Obama administration.

"I'm a long way from that. First of all, we don't know who the next president's going to be. I don't expect to be in government next year. I don't look forward to being in government next year. I've had a great 12 years."