In White House shake-up, Mike Waltz fired as security adviser but nominated as U.N. ambassador

Unnamed sources earlier told Politico, the New York Times, ABC News and other news outlets that Waltz was about to become the first senior-level adviser released by Trump.

Hours after the reports surfaced, Trump announced his plans to nominate Waltz to be the U.S. ambassador to the United Nations.

Trump also said he will name Secretary of State Marco Rubio to replace Waltz as national security adviser on an interim basis.

The Senate must confirm Waltz's ambassadorship and his eventual permanent replacement as National Security adviser.

Trump previously nominated Rep. Elise Stefanik, R-N.Y., to be the U.S. ambassador to the United Nations, but she withdrew her consideration for the position.

Stefanik might run for election as New York's governor, which has led to tensions between her and House Speaker Mike Johnson, R-La., The Hill reported.

Waltz's possible replacement as National Security adviser had been discussed for weeks within the White House, ABC News reported.

Some have suggested special envoy Steve Witkoff might step into the role if it becomes vacant.

Witkoff is representing the United States in negotiations with Russia, Iran and Hamas to try to end the wars in Ukraine and Gaza.

Other potential replacements include Stephen Miller, who is Trump's primary policy adviser; Richard Grenell, who is the president's special envoy for special missions; and Sebastian Gorka, who is the National Security Council's senior director for counterterrorism, Politico reported.

Deputy National Security Adviser Alex Wong also might leave his position, the news outlets reported.

Waltz is a military veteran, a former member of Congress from Florida from 2019 until 2025, and a former member of the House Armed Services Committee.

Waltz accidentally included The Atlantic editor Jeffrey Goldberg in a secure Signal app chat discussing pending aerial strikes against Houthi targets in Yemen on March 15.

Goldberg afterward reported he had been included in the chat due to a mistake made by a Waltz staffer, who intended to include someone else in the chat and not Goldberg.

The military strikes against Houthi targets in Yemen have continued since March 15.

Trump says they won't end until the Houthis stop attacking commercial shipping and U.S. military assets in the Red Sea, the Gulf of Aden and in the air.

This is a breaking news story. Check back for the latest updates.