President Donald Trump said Thursday that he would nominate outgoing national security adviser Mike Waltz to be the U.S. ambassador to the United Nations.
“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 said on Truth Social. He said Secretary of State Marco Rubio would act as "interim" national security adviser.
“I’m deeply honored to continue my service to President Trump and our great nation,” Waltz said on X after Trump’s announcement.
Waltz, a former congressman from Florida, has been on shaky ground with Trump since March after he inadvertently added a journalist to a private chat on the messaging app Signal with other top national security officials to discuss military strikes in Yemen. Three sources with knowledge of the situation had said earlier Thursday that Waltz and deputy national security adviser Alex Wong were expected to leave the administration.
White House officials declined to comment when they were asked about the expected departures.
Trump had initially nominated Rep. Elise Stefanik, R-N.Y., for the high-profile U.N. ambassador post, but he withdrew her nomination in late March, citing Republicans’ razor-thin majority in the House. “She is phenomenal, No. 1. She is a friend of mine,” Trump said at the time, but “we have a slim margin. We don’t want to take any chances.”
Unlike the national security adviser role, the U.N. ambassadorship requires Senate confirmation. Waltz’s involvement in the Signal mishap is likely to be a source of contention in that process.
Screenshots of the Signal chat shared by The Atlantic showed that a user named “Michael Waltz” initially added the magazine’s top editor, Jeffrey Goldberg, to the high-level discussion.
Waltz took responsibility for the incident in an interview with Fox News in March.
“I take full responsibility. I built the — I built the group,” Waltz told host Laura Ingraham. “My job is to make sure everything’s coordinated.”
Trump publicly stood by Waltz in the days after The Atlantic report, telling NBC News, “Michael Waltz has learned a lesson, and he’s a good man.”
But speaking with reporters from The Atlantic last week, he was less steadfast. Trump said Defense Secretary Pete Hegseth, who also participated in the group chat, was “safe.”
“Does he stay longer than Mike Waltz?” The Atlantic’s Ashley Parker asked.
“Waltz is fine,” Trump said. “I mean, he’s here. He just left this office. He’s fine. He was beat up also.”
Despite Trump’s public support of Waltz, he vented privately about his frustration in the days after the incident became public, two Republican sources with knowledge of the conversations told NBC News at the time.
Waltz did not appear to be at a Rose Garden ceremony Thursday morning attended by Trump and many other senior administration officials, and Trump did not mention him in remarks welcoming attendees.
Vice President JD Vance told Fox News in an interview Thursday evening that the Signal chat, in which he participated, was not why Waltz was being moved and that you "can make a good argument that it’s a promotion."
"If the president wanted to fire him over the Signal thing, which, by the way, was a total nothing-burger of a story, he would have just done it, but he actually decided it’s better for Mike to be in this new role," Vance said, calling Waltz a "great guy." "He’s got the trust of both me and the president," Vance said.
Senate Minority Leader Chuck Schumer, D-N.Y., said Waltz deserved to lose his job and called for Hegseth, who discussed details about the attack in the Signal chat, to be the next to go.
“Look, they should fire him, but they’re firing the wrong guy. They should be firing Hegseth,” Schumer said.
Asked how he thinks Waltz's confirmation hearings would go, Sen. Mark Warner, D-Va., said, "I think it would be pretty brutal."
Waltz paid tribute to Trump at a Cabinet meeting Wednesday.
“We’ve had 100 days of your leadership, with respect, with strength,” Waltz said. “It’s an honor to serve you in this administration, and I think the world is far better and far safer for it.”
A Reuters photo showed Waltz appearing to be using a Signal-like app on his phone during the meeting, which White House communications director Steven Cheung shrugged off on X. "Signal is an approved app that is loaded onto our government phones," he wrote.
As a House member, Waltz aligned himself with traditional conservative foreign policy views, though his stance on Ukraine moved closer to Trump’s.
Republicans in Congress who favor continued U.S. military aid to Ukraine viewed Waltz as a counterweight to Vance and others in the administration who have more skeptical views of Kyiv and its cause.
Waltz’s efforts to shape a coherent approach to the Ukraine war and other international challenges were often undermined by Trump’s improvised, unpredictable leadership style.
Before the November election, Waltz had argued for quickly wrapping up the war in Ukraine and said that if Russian President Vladimir Putin rejected peace talks, the United States should then ramp up weapons deliveries to Ukraine. But so far, Trump has not embraced that idea, and he has regularly focused his ire on Ukraine and its president, Volodymyr Zelenskyy.
Waltz’s influence was also diminished by Trump’s reliance on special envoy Steve Witkoff, whom he has dispatched to hold talks with Putin, as well as leaders in the Middle East.
Rubio’s appointment as interim national security adviser is his third as acting head of an agency, in addition to his duties as the country’s top diplomat. Trump also named him acting head of the U.S. Agency for International Development and acting head of the National Archives and Records Administration in February.
Trump heaped praise on Rubio at Thursday’s Rose Garden event before the announcement. “Marco, when I have a problem, I call up Marco. He gets it solved,” Trump said.
