Republican U.S. presidential candidate Mitt Romney and his new running mate, Wisconsin Congressman Paul Ryan are splitting up Monday to campaign in two swing states that could determine the outcome of the 2012 presidential election.

Romney is set to campaign in Florida, while Ryan is heading to Iowa.

The two campaigned Sunday in North Carolina, then in Ryan's home state of Wisconsin. Both states are considered key battlegrounds in the race for the White House.

Romney is hoping Ryan's work in Congress to slash spending and create smaller government will help energize the Republican Party's conservative base.

They launched their four-day, multi-state campaign bus tour Saturday, immediately after Romney announced the 42-year-old congressman as his vice presidential pick.

President Barack Obama's campaign blasted the choice, saying Ryan proposes a budget that would cut taxes for the wealthy and hurt the middle class and seniors.

Romney, the presumptive Republican nominee, will face President Obama, a Democrat, in the November 6 election.