Mitt Romney says there may be differences between his own budget plan and running mate Paul Ryan's, but he isn't volunteering any of them.

Instead, the Republican presidential candidate said Monday that he and his running mate are "on the same page."

Romney said he was "sure" there are places where his budget is different than Ryan's. But he refused to say what specific policies his budget would include that would differ from the Wisconsin congressman's detailed proposal.

Ryan's budget makes dramatic changes in America's social safety net. Romney says that Ryan's plan is better than President Barack Obama's.

Romney spoke to reporters in Miami as he continued a four-state bus tour.