President Barack Obama has used an appearance on a US talk show to criticise Mitt Romney’s comments that nearly half of Americans are "victims" who depend on the Government.
Mr Obama capitalised on the remarks as more leaked video footage of his Republican rival emerged - this time with Mr Romney appearing to declare how he would carry out a terrorist attack on America if he was leader of Iran.
After the Republican candidate was secretly filmed telling donors his job was "not to worry" about the 47% of American voters who back Mr Obama because they pay no income tax and depend on the state for healthcare, food and housing, the President told a popular US TV show that the occupant of the White House must "work for everyone, not just for some".
Speaking on the Late Show with David Letterman, Mr Obama responded: "One thing I've learned as president is that you represent the entire country.
"There are not a lot of people out there who think they are victims or simply entitled."
Mr Romney has since insisted that his remarks, posted on the internet by left-leaning magazine Mother Jones, are evidence of a fundamental difference with Mr Obama's Democrats over the economy, adding the US government should not "take from some to give to the others".
Meanwhile, new secret video footage has been posted which pundits say raises further questions over the Republican candidate's foreign policy credentials.
Mitt Romney Mitt Romney boards a plane on the election trail
At the same donors meeting, held in Florida in May, Mr Romney said: "If I were Iran, a crazed fanatic, I'd say let's get a little fissile material to Hezbollah, have them carry it to Chicago, and then if anything goes wrong, or America starts acting up, we'll just say, 'Guess what? Unless you stand down, why, we're going to let off a dirty bomb'.
"I mean this is where we have - where America could be held up and blackmailed by Iran, by the mullahs, by crazy people. So we don't have any option but to keep Iran from having a nuclear weapon."
Further filming showed the presidential candidate seemingly dismiss Middle East peace talks.
He said: "I look at the Palestinians not wanting to see peace anyway, for political purposes, committed to the destruction and elimination of Israel, and these thorny issues, and I say there's just no way.
"You move things along the best way you can. You hope for some degree of stability, but you recognise that this is going to remain an unsolved problem -- and we kick the ball down the field and hope that ultimately, somehow, something will happen and resolve it."
Despite Mr Romney's remarks, the presidential race remains neck-and-neck with just seven weeks to go until the November 6 election.
According to the latest AP-GfK poll, Obama is supported by 47% of likely voters and Romney by 46%.