Ahead of Mr Obama's official re-election campaign launch Saturday, his campaign took aim at Mr Romney's wealth and business career, a day after the president questioned whether the Republican would have taken out Osama bin Laden.
Mr Obama's first negative campaign ad slammed Mr Romney for, as CEO of investment firm Bain Capital, outsourcing US jobs to places like Mexico and China.
It said as governor of Massachusetts, Mr Romney sent state jobs to India, taking direct aim at Mr Romney's claim that his corporate past gives him the expertise needed to speed up the stuttering US recovery.
"It's just what you'd expect from a guy who had a Swiss bank account," a narrator said, at the end of an ad that will air in swing states Ohio, Virginia and Iowa.
Later, Mr Obama's campaign directed supporters to a webpage on his campaign website showing a map displaying foreign nations where Mr Romney and his wife had money, including Bermuda, the Cayman Islands, Luxembourg, Germany, Australia, and Switzerland.
The campaign said the graphic was based on information gleaned from the Romney's tax returns for 2010.
In 2010, Mr Romney paid a lower tax rate than many middle class Americans -- 13.9 per cent on income of $21.7 million -- a point the Obama campaign is using to suggest the Republican profits from an economy weighted against the middle class.
His estimated income from 2011 was $20.9 million and his fortune is estimated at about $250 million. He has requested a six month extension to file his federal return for 2011, prompting demands for transparency from the Obama camp.
Mr Obama and First Lady Michelle Obama on Saturday will hold rallies in Ohio and Virginia, both seen as stepping stones on the road back to the White House, in their official kickoff of the sprint to November's election.
On Monday, Mr Obama questioned whether Mr Romney would have taken the tough decision he did a year ago to order a special forces raid to kill Al Qaeda leader Osama bin Laden in Pakistan.
"I said that I would go after bin Laden if we had a clear shot at him and I did it," a steely Mr Obama said in a White House press conference.
"If there are others who said one thing and now suggest they would do something else, I would let them explain it," Mr Obama said.
On Tuesday, Mr Romney hit back, insisting that he would have taken such a step, despite criticizing Obama back in 2007 for saying he would infringe Pakistani sovereignty if Islamabad refused to act on intelligence about terror suspects.
"These silly kinds of attacks, it's like, what has that got to do with getting our economy going?
"Of course, I would have taken out Osama bin Laden, but what's the right course for the economy?" Mr Romney said on CBS "This Morning."
"These are important issues people care about. The president's not talking about them. My campaign is."