"If I worried about what the media said I wouldn't get much sleep, and I sleep pretty well," Romney told CBS News' Jan Crawford during an interview Sunday in Jerusalem.
"They tried that on George Herbert Walker Bush. He was a pretty great president and anything but," Romney said, adding that he doesn't "recall" ever being called a wimp before.
Romney's interview came shortly after his senior adviser, Dan Senor, said Mitt Romney would back an Israeli attack of Iran if all other diplomatic options had been exhausted.
The Republican presidential candidate softened the statement but reaffirmed his support of Israel.
"I respect the right of Israel to defend itself," Romney said in an interview with CBS News' Jan Crawford in Jerusalem. "We stand with Israel. We're two nations that come together in peace and we want to see Iran dissuaded from its nuclear folly."
Although Romney's adviser vocalized a major difference in current American foreign policy with the pronouncement that Romney could back an Israeli attack on Iran, Romney said he would not provide any additional specifics because he's "on foreign soil."
"I don't want to create new foreign policy for my country or in anyway distance myself" from current American foreign policy, he said, admitting that it would be a major shift in Washington's position. "Are there differences between [Obama and me]? Of course. But being on foreign soil, particularly being here in Israel, this isn't the right time for me to draft those out.
"[W]e should use every diplomatic and political vehicle that's available to us to keep Iran from becoming a nuclear capability state. Those actions should be executed with the greatest speed that we can muster. If all those options fail... then we do have other options and we don't take those other options off the table. But that's as far as I'm willing to go in terms of discussing this matter while on foreign soil," Romney said.
The chair of the Democratic Party, Rep. Debbie Wasserman-Schultz, D-Fla., said on "Face the Nation" that Romney's comments are "emblematic" of his skills as a statesman.
"I think that's emblematic of and revealing of how Mitt Romney's entire trip overseas has gone so far," she told Bob Schieffer. "I think he's demonstrated, pretty repeatedly since he's been out of the country, that he lacks the experience, he lacks the preparation and the diplomatic skills to be able to be the commander in chief, to be the President of the United States."
"President Obama has said that it is a top priority of the United States of America to ensure that Iran never achieves its nuclear ambition and that all options are on the table, and in fact that include all options, a military option being one of those," Wasserman-Schultz said. "Contingency plans exist for those military options and, you know, if Mitt Romney believes that it is time to go to war to address Iran's quest to achieve their nuclear ambition, then he should say that," she added.
Romney, however, said Iran is the biggest threat to American national security, and, subtly and repeatedly knocked President Obama's foreign policy prescriptions, by saying that Iran is "five years closer" to a nuclear weapon.
"Iran's nuclearization is the greatest single national security threat America faces. That's of great concern to me," Romney said. "And all our efforts should be focused on making that our first priority keeping them from having that nuclear capacity our first priority."
Romney, who is meeting with Israeli officials, including Prime Minister Benjamin Netanyahu, said that some of the seven steps he laid out at a conference five years ago aimed at dissuading Iran from obtaining a nuclear weapon have not been implemented - enabling them to advance their nuclear pursuit.
"Since that time not all of those steps have been put in place," adding that "We're five years closer to a nuclear Iran."
Crawford asked Romney about his campaign which has focused on the former Mass. governor and Bain Capital founder's business experience. "Would you say that foreign policy is the area where you're weakest?" she asked. Romney invoked another former governor-turned-president, Ronald Reagan, as a model.
"I would say that foreign policy is a place where intelligence, resolve, clarity and confidence in cause is of extraordinary importance," he said. "Ronald Reagan was one of our great foreign policy presidents. He did not come from the Senate, he did not come from the foreign policy world; he was a governor. But his resolve, his clarity of purpose, his intelligence, his capacity to deal with complex issues and solve tough problems served him extremely well.
"And if I were elected president, I hope I could rely upon those same qualities."
When asked about a statement in an upcoming issue of Newsweek by Senator John McCain, R-Ariz., that Romney "has not got a lot of instincts on some of these national-security issues, but he has the right instincts," Romney said he respects Sen. McCain "a great deal and I believe he has many ideas and suggestions that I would certainly want to avail myself of if I was in a setting that required the input of other leaders. Senator McCain would be one of those that I'd want to hear from."