Russian President Vladimir Putin is “clearly a slow learner,” Defense Secretary Jim Mattis said Saturday while discussing efforts to deter Kremlin’s regional aggression.

“This is a very complex situation because Mr. Putin is clearly a slow learner,” Mattis told Fox News’ Bret Baier during a panel discussion at the Reagan Defense Forum. “He is not recognizing that what he is doing is actually creating the animosity against his people. He is not acting in the best interest of the Russian people.”