California Gov. Gavin Newsom called President Donald Trump's directive to restart testing nuclear weapons in the U.S. "weakness masquerading as strength."

"This is classic Trump and Trumpism. This guy is historically weak, and these are acts of a weak person that is trying to appear strong," Newsom told NBC News' "Meet the Press."

Trump said Wednesday that he had directed the Defense Department to “immediately” start testing nuclear weapons, which the U.S. hasn’t done since 1992.