"I can say he will be playing a major role and was happy to honor Gov. Romney’s request to participate in the Tampa convention," Cohen said in an email. "Mr. Trump’s role will be something unique and interesting that will be memorable for the convention-goers as well as those across the nation watching from home."

Trump tweeted last Friday that he had turned down an offer to speak at the convention, and his name did not appear on the first wave of convention speakers released by the Republican National Committee.

The evening before the convention kicks off, Trump will be honored as "Statesman of the Year" by the Republican Party of Sarasota County, Fla., at a dinner event.