() President Donald Trump announced on Truth Social that national security advisor Mike Waltz was being nominated U.S. ambassador to the United Nations.

Reports surfaced Thursday morning that Waltz was on his way out from his current role following an incident where he mistakenly included a journalist on a Signal group chat discussing strikes on Yemen.

“From his time in uniform on the battlefield, in Congress and, as my National Security Advisor, Mike Waltz has worked hard to put our Nation’s Interests first. I know he will do the same in his new role,” Trump posted on Truth Social.

He announced that Secretary of State Marco Rubio would serve as interim national security advisor.

“I’m deeply honored to continue my service to President Trump and our great nation,” Waltz said on X.

As with all ambassador appointments, Waltz will have to be confirmed by the Senate, where lawmakers can be expected to grill him on the security implications of his mistake and the use of an unapproved platform to discuss sensitive information.

Politico first reported that Waltz and his deputy, Alex Wong, will no longer hold positions in the White House.

Waltz’s exit was confirmed by multiple sources familiar with the situation, according to several reports.

Calls for Waltz’s departure have continued since a journalist was mistakenly included in a group chat with top Trump officials on the messaging app Signal.

The chat, created by Waltz and led primarily by Defense Secretary Pete Hegseth, discussed plans for a strike on Houthi rebels in Yemen.

The messages detailed a timeline for the attack, including specific weapons that would be used.

In the aftermath, Waltz, in a cable TV appearance, said he took “full responsibility” for the group chat: “We made a mistake. We’re moving forward.”

Previously, Trump told the media, “Michael Waltz has learned a lesson, and he’s a good man.” Trump has also stood by Hegseth amid calls for his removal.

The White House as a whole has downplayed the group chat’s potential for security risks, with Trump in March calling the error “the only glitch in two months,” and not “a serious one.”

It is unknown who would take over for Waltz, who is the first departure of Trump’s second term.

This is a developing story. Refresh for updates.