I’m not sure it was actually meant to be a joke. It was more a barb aimed at the press for continuing to ask the same exact question to Trump again and again. I predict that particular question will no longer be asked.
Of course, President Trump is not going to inform anyone outside of a very tight circle of military plans because the information would be leaked immediately destroying any possibility of success.
even so, funny as hell
It was supposed to be a question for his guest, but the insolent fellow directed his snarky inquiry to the President of the United States — and got the slap-down he deserved.