President Barack Obama's conduct during the debate over the debt ceiling has divided the country and will inflict damage that will last well after the battle is over, former New York Stock Exchange director and Wall Street stalwart Ken Langone said.

While he believes a debt deal will get done and in fact favors a plan closer to what the Democrats are proposing, Langone told CNBC that Obama's behavior has been "unpresidential."

"He is dividing us as a nation," Langone said. "He's not bringing us together. He's willfully dividing us. He's petulant."