US President George Bush said John McCain has a lot of work left to convince Republicans, he is a "solid" conservative, but said he would support his one-time rival if McCain wins the party's presidential nomination.
"I know him well. I know his convictions. I know the principles that drive him. And no doubt in my mind he's a true conservative," Bush said in an interview on Fox News on Sunday.
But, Bush added, "I think that if John's the nominee, he has got some convincing to do to convince people that he is a solid conservative."
"And I'll be glad to help him if he's the nominee."
Bush defended McCain, who ran against him in the 2000 presidential race, against criticism from the party's right-wing that McCain is not conservative enough to represent them.
"Look, he's very strong on national defence. He's tough fiscally. He believes that tax cuts ought to be permanent. He's pro-life. I mean, his principles are sound and solid as far as I'm concerned," Bush said.
But Bush, in his final year as president, refused to declare his preference between McCain and former Arkansas governor Mike Huckabee, who has remained in the race despite having little chance of overcoming McCain's massive lead.
"I do want to make sure that you don't rope me into getting into this primary before it ends, because we have another conservative candidate in Mike Huckabee still running," Bush told Fox.