On foreign policy, Romney says President Obama has damaged relations with longtime ally Israel and has not been tough enough with Iran, China and Russia.

“And in dealings with other nations [President Obama] has given trust where it is not earned, insult where it is not deserved and apology where it is not due,” he said.

Romney has focused on the weak economy. But public opinion polls show he faces a challenge because voters find the president more likeable, says American University expert Jennifer Lawless.

“There’s no question that Mitt Romney has a problem on this front," she said. "But in a lot of ways maybe it’s time to just embrace that problem and say to the American people, ‘Look, I know that you don’t like me that much but I can get this country moving in the right direction.’”

Romney is less well known than President Obama, something both campaigns will try and address in the final weeks of the campaign, says Quinnipiac pollster Peter Brown.

“There is a race to define Mitt Romney to the American voter and the race is between the Obama people who want to define him negatively and the Romney people who want to define him positively. The campaign that does the best job defining Mitt Romney is going to win,” he said.

Mitt Romney is 65, is married to his wife Ann since 1969, and they have five sons.