U.S. President Barack Obama and Republican rival Mitt Romney criss-crossed America on Sunday, continuing with their scramble in a two-day final dash for the U.S. presidential election.

Both men launched a full-scheduled campaign whirl across battleground states that would likely decide the final outcome.

Obama began his Sunday in New Hampshire, flied to Florida and all-important Ohio later and ended in Wisconsin, as an exhausting final push to solidify his standing in the key swing states.

With former President Bill Clinton at his side to help deliver the final pitch to voters, Obama attacked Romney's recent argument about bringing "real change" to fix the country.

"We know what change looks like and what he's selling ain't it," the president told supporters in New Hampshire on Sunday.

The Obama campaign also cited national polls and stressed their confidence in early voting and ground game in the swing states.

Obama campaign spokeswoman Jen Psaki said about 44 percent of Florida voters have already cast early ballots, and Obama led over Romney by seven points, which means "Romney would need to win the remaining voters by six points in order to tie up the race."

She also said the president led by 63 percent to 35 percent among the 28 percent of Ohio votes that have already been cast.

"We feel very confident about Ohio. We feel good about where we've set ourselves up with early vote. We feel great about our ground game. And we feel great about how we're closing this race, and confident that that's going to be in a Democratic column on Tuesday," said Psaki aboard Air Force One en route New Hampshire.

"But we know we need to get the people out to win. And so that's what the next couple of days is about. That's why the President is making so many stops. That's why he'll see so many people between now and when the polls close on Tuesday," said Psaki.

Romney also rushed across Iowa, Ohio and Virginia before making his first appearance in Democratic-leaning Pennsylvania in months, throwing out ads in the homestretch.

"He calls them 'forward.' I call them 'forewarned,'" said Romney in a campaign event in Iowa, referring to Obama's campaign message.

At another event in Cleveland, Ohio, Romney told voters that Obama had "just two more days, not four more years."

A latest Pew poll, released on Sunday, found Obama led ahead 48 percent to 45 percent among likely voters nation-wide, a three point bump in his favor.

Obama's handling of Hurricane Sandy's aftermath was approved by 69 percent of likely voters, even with 46 percent of Romney supporters.

A new poll conducted by USA Today and Gallup showed likely voters in swing states split 48 percent to 48 percent between Obama and Romney.

According to new NBC News/Wall Street Journal/Marist polls released on Saturday, Obama still held a six-point advantage over Romney among likely voters in Ohio, with 51 percent to 45 percent. In Florida, the president gets support from 49 percent of likely voters, while his GOP challenger gets 47 percent.

These two states are two of the biggest prizes in Tuesday's presidential contest. An Obama victory in Ohio, which has 18 electoral votes, would put him tantalizingly close to getting to the 270 electoral votes needed to win a second term, and a Romney win would put Obama in the defensive.

Florida, which has 29 electoral votes, is a must-win state for Romney. His loss in the state would practically mean Obama's reelection, even without Ohio.