In the battleground state of Iowa, Republican Mitt Romney called for change in the White House and attacked President Obama's economic policies and leadership, saying the incumbent has failed the nation.

Obama "doesn't have any prospect of meeting the challenges of the times," Romney said. "Americans are ready for change, for growth, for jobs, for more take home pay, and we're going to bring it to them."

Adopting the theme that Obama used to win the presidency in 2008, Romney said he and running mate Paul Ryan represent "real change, change that offers promise, promise that the future will be better than the past."