A few moments later, after acknowledging that there were news networks broadcasting him live, Trump made the announcement, confirming news reports from earlier in the day.
"We are going to appoint ‘Mad Dog’ Mattis as our secretary of defense," he said. "But we’re not announcing it until Monday so don’t tell anybody."
Mattis will not be able to be confirmed unless Congress passes legislation allowing the retired general to bypass a rule dictating that individuals who have served in the military within the past seven years cannot serve as secretary of defense. Congress has only granted such a waiver once before.
Sen. Kirsten Gillibrand (D-NY) has already said she would not support a waiver allowing Mattis to lead the Defense Department.
"While I deeply respect General Mattis’s service, I will oppose a waiver. Civilian control of our military is a fundamental principle of American democracy, and I will not vote for an exception to this rule," she said in a statement.