() President Donald Trump has nominated outgoing national security adviser Mike Waltz to serve as U.S ambassador to the United Nations.

John Bolton, who served as Trump’s national security adviser in his first term, told “Morning in America” the nomination offers Waltz a “soft landing” within the administration.

As with all ambassador appointments, Waltz must be confirmed by the Senate. Bolton noted that Waltz’s confirmation hearing will likely be dominated by questions surrounding his handling of classified information.

Waltz has faced scrutiny for weeks after 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.

Waltz was also spotted by reporters using the Signal app during Trump’s Cabinet meeting the day before his exit as national security adviser.

Bolton expressed surprise at seeing him use the app, since everyone in the Signal group chat already had 24/7 access to U.S. government secure communications.

“The lesson that everybody should have learned is that you communicate classified information over secure communications channels,” he said. “There’s no reason to use Signal or any so-called encrypted, privately owned communications channel. It’s far too risky. So, to see it again, I’m sure that will be half an hour of questioning at his confirmation hearing.”

Secretary of State Marco Rubio will serve as interim national security adviser.

Bolton noted that a similar situation occurred once before with Henry Kissinger, who served as secretary of state and national security adviser during the height of the Watergate scandal. Still, Bolton said he doubts anyone can effectively manage both roles today, given the current complexities of modern national security decision-making.

“It was an extraordinary situation. It was literally a constitutional crisis. So not a good sign, not a good look, for the Trump administration to be doing it,” Bolton said.

’s Tom Dempsey and Anna Kutz contributed to this report.