President Trump spoke to reporters from Air Force One Sunday night, answering questions from the national security advisor to an offer to send troops to Mexico to fight cartels.

"I think it will be a brutal confirmation hearing," Senate Intelligence ranking member Mark Warner, D-Virginia, said on CNN. "I think he's going to have tough questions, not only from Democrats but from Republicans.

National security adviser Mike Waltz is leaving his White House post, although soon after reports about his departure were published, President Trump announced he plans to nominate him to be ambassador to the United Nations.