"I don't think that Gov. Romney is somehow responsible for the death of the woman who is portrayed in that ad," the president told the White House press corps when asked about a controversial ad from the super PAC Priorities USA Action tying the Republican candidate to a tragic death from cancer. "But keep in mind this is an ad that I didn't approve, I did not produce, and as far as I can tell, has barely run."

The man featured in the ad has also appeared on an Obama campaign conference call, but Obama's team has denied knowledge of his story.

Obama also distanced himself from criticism of Mitt Romney's record at Bain Capital, saying, "Nobody accused Romney of being a felon." Obama deputy campaign manager Stephanie Cutter suggested earlier this year that the Republican nominee "may have committed a felony."