HIGH POINT, N.C. – Cheered by the biggest crowds of his campaign, Republican Mitt Romney declared Sunday that 42-year-old running mate Paul Ryan is ready to be president, but said his own budget plan, not the more detailed proposals of his partner, will be the basis of his White House bid.

"I have my budget plan," he said. "And that's the budget plan we're going to run on."

Earlier, Romney walked a careful line as he campaigned with Ryan by his side in North Carolina, singling out his running mate's work "to make sure we can save Medicare." But the presidential candidate never said whether he embraced Ryan's austere plan himself, and he addressed the matter more directly in a "60 Minutes" interview, with Ryan still with him, that aired Sunday night on CBS.