Waltz was at the center of the Signal chat controversy, in which a journalist was accidentally included in a discussion of sensitive military information.

White House national security advisor Mike Waltz is set to depart the administration, according to two people familiar with the matter Thursday, marking the first major staff shakeup of President Trump’s second term.

President Donald Trump announced his choice to serve as ambassador to the U.N. after Rep. Elise Stefanik withdrew her nomination amid concern over the GOP's slim majority in the House.