"What I did learn is that our leadership, Barack Obama, did not follow what our experts and our truly -- when they call it intelligence, it's there for a reason, what our experts said to do," he said during the forum.
"In almost every instance, and I could tell, I'm pretty good with the body language, I could tell. They were not happy. Our leaders did not follow what they were recommending."
Trump did not get into other specifics about the briefing, which is given to each of the presidential candidates after their nomination conventions. The idea behind the briefings is to bring the candidate up to speed so they can be ready to go on Day One of their presidency.
Lauer had asked Trump if he learned anything in the briefing "that makes you reconsider some of the things you say you can accomplish, like defeating ISIS quickly."