Mike Waltz, Donald Trump’s national security advisor, is set to leave his White House post amid continued fallout weeks after he accidentally invited a journalist into a chat between top national security officials discussing plans for Yemen airstrikes.

Trump had publicly stood by Waltz after his national security adviser and other members of the chat vigorously denied sharing any classified war plans on the publicly available app Signal. The chat was revealed when Jeffrey Goldberg, the editor-in-chief of The Atlantic, published a March 24 story detailing how Waltz accidentally invited him into the communications.

But behind-the scenes, the embarrassing mishap ‒ which even Trump started referring to as “Signalgate” ‒ took a toll on the relationship between Trump and Waltz, a former Republican congressman from Florida.