Reported here, too--
Link to video
Background is: he, in error, is operating under the assumption that China and Korea ? tested nuclear weapons, when they only tested weapons capable of delivering them; then he ordered (as yet not happened, planning stage) nuclear tests to be done on American soil.
So, all things considered, when he asked for the nuclear codes, the Chairman of the Joint Chiefs of Staff (if I understood correctly) allegedly flat out said, "No."