U.S. President Barack Obama and Mitt Romney, the man who hopes to deny him a second term in the Oval Office, appeared in duelling interviews on Sunday on 60 Minutes, the highly rated CBS news show that has long wielded influence over American presidential politics.

In an interview airing two days before Obama was slated to address the United Nations, the president brushed off repeated accusations by Romney that he's weak on national defence, adding that if Romney "is suggesting that we should start another war — he should say so."

Despite recent setbacks Mitt Romney says his campaign for the White House "doesn't need a turnaround." (CBS/Associated Press)

Obama defended his efforts to end the wars in Iraq and Afghanistan, and touted his successful attempts to track down and eliminate Osama bin Laden, the mastermind behind the Sept. 11, 2001, terrorist attacks.

He suggested he wasn't going to be cajoled into any course of action in terms of action against Iran from Romney or Israeli Prime Minister Benjamin Netanyahu.

"When it comes to our national security decisions, any pressure that I feel is simply to do what's right for the American people," he told CBS's Steve Kroft. "And I am going to block out any noise that's out there."

Obama, greying and looking fatigued during his interview, sat down with 60 Minutes on Sept. 12, the day after America's Libyan ambassador was killed in an eruption of anti-American violence in the Middle East.

He had harsh criticism for Romney's much-maligned response to the violence. Romney erroneously stated that the White House apologized to the perpetrators of the violence in the early hours of the turmoil.

"It appears that Gov. Romney didn't have his facts right," Obama told 60 Minutes.

"Gov. Romney seems to have a tendency to shoot first and aim later. And as president, one of the things I've learned is that you can't do that; that, you know, it's important for you to make sure that the statements that you make are backed up by the facts; and that you've thought through the ramifications before you make them."

He also deflected criticism from Romney over his decision not to sit down with Netanyahu this week at the UN.

Difficult questions

Romney, meantime, in his own interview, said that decision "sends a message throughout the Middle East that somehow we distance ourselves from our friends and I think the exact opposite approach is what's necessary."

Both men were asked difficult questions about their vulnerabilities.

Romney has been under fire for recently revealed remarks that almost half of Americans feel they're entitled to government handouts.

But even as Obama pulls ahead of him nationally and in key battleground states, Romney said his campaign "doesn't need a turnaround."

"I've got a very effective campaign. It's doing a very good job. But not everything I say is elegant."

'Not everything I say is elegant'—Mitt Romney

Obama, plagued by an economic recession and a stubbornly high unemployment rate, was asked why he's had little success pushing a job creation bill through Congress or to kickstart a sputtering economic recovery.

"We still have a long way to go," he said, but pointed to 30 months of job growth and tax cuts for middle-income Americans. His opponent's agenda, he added, would amount to going "backwards to the very policies that got us into this mess."

"The problem that Gov. Romney has is that he seems to only have one note: tax cuts for the wealthy and rolling back regulations as a recipe for success. Well, we tried that vigorously between 2001 and 2008. And it didn't work out so well."

Obama admitted some shortcomings, saying his most significant letdown during his four years in office has been an inability to change the culture of the U.S. capital.

"My biggest disappointment is that we haven't changed the tone in Washington as much as I would have liked," Obama said.

'We still have a long way to go'—Barack Obama

"I'm the first one to confess that the spirit that I brought to Washington, that I wanted to see instituted — where we weren't constantly in a political slugfest but were focused more on problem-solving … I haven't fully accomplished that. Haven't even come close in some cases."

His mistake was not involving Americans to help him bring about the change he promised while running for president four years ago, he added.

"One of the things I've realized over the last two years is that that only happens if I'm enlisting the American people much more aggressively than I did the first two years," Obama said.

But he also pointed to some of his accomplishments since becoming president, including passing his sweeping health-care overhaul and implementing reforms to the country's financial industry.

"Change has happened, and positive change for the American people," he said.

Devil in the details

In Romney's interview, the Republican presidential hopeful harshly criticized Obama's vision for America, saying it involved too much government involvement in the lives of Americans.

He was asked why Americans should trust him given he has changed his opinion on several fronts. He was pro-choice, for example, 10 years ago when he was governor of Massachusetts; he's now pro-life.

"The principles I have are the principles I've had from the beginning of my political life. But have I learned? Absolutely," he said.

When pushed by CBS's Scott Pelley to provide details about his tax proposals, Romney deferred.

"That's something Congress and I will have to work out together," he said, adding that although "the devil's in the details, the angel is in the policy, which is creating more jobs."

He defended the tax rate that millionaires like him pay — below 15 per cent on investment income.

"I think it's the right way to encourage economic growth — to get people to invest, to start businesses, to put people to work," he said.

When asked how he thinks he'll fare on Nov. 6, Romney replied with a smile: "Oh, I think I'm going to win."

In 10 days, Romney and Obama will have a chance to go head to head on the issues. The first of three presidential debates is being held on Oct. 3 in Denver.