MIAMI - Asked three times today whether there are parts of Rep. Paul Ryan's Medicare plan with which he disagrees, Mitt Romney offered no specifics, saying only that "there may be."

"Well, the items that we agree on I think outweigh any differences there may be," Romney said of his running mate's Medicare overhaul plan at a news conference on the tarmac of the Miami airport.

"We haven't gone through piece by piece and said, 'Oh, here's a place where there's a difference.'

"I can't imagine any two people, even in the same party, who have exactly the same positions on all issues," Romney added, before explaining that his plan for Medicare is "very similar" to Ryan's.

Romney's website says that Ryan's plan "almost precisely mirror's Mitt's." But Romney overlooked any differences today.

"I'm sure there are places that my budget is different than his but we're on the same page, as I've said before. We want to get America on track to a balanced budget," Romney told one reporter.

And in a follow-up question about whether there were any specific policies in his budget on which he would run that are different than Ryan's plan, Romney was brief and frank in his response.

"There may be," the candidate said. "We'll take a look at the differences."