From the September 12 edition of Fox News' The O'Reilly Factor:
BILL O’REILLY (HOST): The Iraq war began in 2003, before the shooting started, Trump told Neil Cavuto that Iraq was not the main threat to the U.S.A., North Korea was. In March of 2003, he told Cavuto the conflict looked like a military success. He did not openly begin criticizing the war until September 2003. From then on, he wasn't supportive of the effort at all. So looking at all the data, all the data, Trump was never a big fan of the Iraq war, even before it started. He talked to Howard Stern on the radio about a potential war in Iraq and was kind of, well maybe -- well that kind of thing. Never a big fan of it.