Mitt Romney will do anything to help John McCain become president. He'll even serve as McCain's vice presidential running mate if he's asked, the onetime Republican candidate told FOX News.

The former Massachusetts governor said he's sure McCain has a long list of "terrific people" to choose from as a running mate, but he wouldn't reject an offer.

"I think any Republican leader in this country would be honored to be asked to serve as the vice presidential nominee, myself included. Of course, this is a nation which needs strong leadership, and if the nominee of our party asked you to serve with him, anyone would be honored to receive that call, and to accept it, of course," Romney said on Hannity & Colmes. It was his first televised interview since dropping out of the presidential race.

Romney said he expects McCain and his advisers will choose a running mate based on several factors.

"He's going to have a process for doing that, which will begin by saying which person or people has the skills to actually become president, which could strengthen the administration and strengthen our nation at a critical time, and perhaps who could help in some political ways, who could help in some key states or with key constituencies," he said.

Romney became a favorite of the conservative base during the campaign and still has 251 delegates in his pocket. He shocked supporters by dropping out during the Conservative Political Action Conference, two days after Feb. 5, Super Tuesday.

Romney told the conservative activists that it would be better for the party not to have a drawn-out fight that could jeopardize a victory in November. He urged conservatives to get behind McCain, and he said McCain's national security credentials would be an asset for the country. A week later he formally endorsed his former rival.

"There really are no hard feelings" between him and the Arizona senator over the tough and sometimes bitter direction the campaign took, Romney said. Both of them fought for the positions they thought were best for the nation.

Romney added that he would be happy to discuss any issues with McCain if the candidate sought his advice on appealing to conservatives.

But he is not going to dispense any advice off the cuff, he said, because "I'm not going to try to guide the guy who won. ... Let's not forget, he won the primaries, he won the caucuses, he became the nominee, so the positions which he has are ones which have been successful in the final analysis."

Romney said after he withdrew from the race, he took a break and visited with his grandchildren. He also spent time reflecting on his "experiences of a lifetime," but he hasn't "given a lot of thought" to a future presidential bid.

"That's like asking a woman after she's just delivered the baby, 'Do you want to get pregnant again?'" he laughed. "Let's let some time pass."

The former candidate said he is now working on a schedule that will include fund-raisers and events for congressmen, senators and governors who supported his candidacy, as well as fulfilling other requests made of him.

"I will do whatever Senator McCain asks for me to do in his campaign to help out in any way that I can," Romney said. "I want to make sure that we have conservative leadership guiding our country. ... Now is the time for us to come together and support his candidacy."

Romney said he hopes Barack Obama will be the Democratic nominee because he thinks the distinction between McCain and Obama will be easier to make than the one between McCain and Hillary Clinton.

"With Senator Clinton, there's some confusion in perception that somehow being there while her husband was president made her a foreign policy, national security experienced person. She's not. She doesn't have any more experience really of a significant nature than Barack Obama does," Romney said.

He added that when it comes to a general election, it will be evident to voters that Obama "is in no significant way qualified to lead the country in a time of war, to lead the country out of an economic challenge. This is not a person who can stand up to Senator McCain."

Romney said while Clinton promotes experience, she is vulnerable. "My dad used to say, 'There's nothing as vulnerable as entrenched success,'" he said. "And now you look at the delegates, looks like she's going to have to fight at this point."