GOP vice presidential candidate Paul Ryan told hundreds of seniors how he and Mitt Romney, if elected, would protect Medicare, while President Obama argued their plan would only increase participants' cost as both camps Saturday traded jabs on the hot campaign topic of Medicare in the battle to win over seniors by November.

Ryan made his pitch at The Villages, a sprawling retirement community in central Florida, where he walked on stage with mother Betty Douglas Ryan, a Medicare recipient.

"Our solution to preserve, protect and save Medicare does not affect your benefits," Ryan told the crowd. "It's a promise that must be kept. But in order to make sure we can guarantee that promise we must reform it for my generation."

The Wisconsin congressman and House Budget Committee chairman said Medicare will remain unchanged for those 55 and older and proposed a plan that would give future participants the option to use a private insurer.