"Callista Gingrich. Karen Santorum. Ann Romney," The Hollywood Reporter quoted De Niro as saying during his opening remarks at Monday night's $5,000-a-plate event, which Obama's wife, Michelle attended. "Now do you really think our country is ready for a white first lady?"
CNN reported Obama's campaign press secretary Olivia Alair called the joke "inappropriate" Tuesday.
De Niro later issued a statement explaining he was trying to make a joke and never meant to offend anyone.
"My remarks, although spoken with satirical jest, were not meant to offend or embarrass anyone -- especially the first lady," the 68-year-old "Raging Bull" and "Meet the Parents" star said.