Hours after accepting his party's presidential nomination, Romney told a rally in Florida that despite Obama's promises of four years ago, the Democratic incumbent had failed to cut the country's budget deficit or create as many jobs and new businesses as he said he would.

"Almost every measure he described he has failed to perform upon. And the reason for that is not that he wasn't trying, in my view. It's he was pulling in the wrong direction. He didn't know what it takes to actually make the economy work," Romney said.

Romney later planned to visit the Gulf Coast state of Louisiana, where Hurricane Isaac left wide swaths of the state in murky floodwaters and killed five people. Obama is visiting the state on Monday, the day before Democrats start their national convention to officially nominate him for a second four-year term.

Romney - a one-time venture capitalist and former governor of Massachusetts - says he can boost the country's sluggish economy with lower taxes and less government regulation.  Obama, who was to visit the key state of Texas Friday, says a Romney presidency would result in a return to policies that led to the country's worst economic downturn since the 1930s.

Nationwide voter surveys show the two candidates in a virtual tie 10 weeks ahead of the November 6 election. 

Romney said that if elected president, he will use a five-step plan to improve the economy and create 12 million jobs. He also promised "less flexibility and more backbone" in global diplomacy, along with "more loyalty" to U.S. allies such as Israel.

The convention night included an appearance from film star Clint Eastwood, who received a roar from the crowd when he referred to politicians as "employees" of citizens who need to be let go when they do not "do the job."