Trump names Secretary of State Rubio as acting National Security Adviser, taps Mike Waltz for U.N. envoy

Mr. Trump said Mr. Rubio will continue to serve as Secretary of State.

“I am pleased to announce that I will be nominating Mike Waltz to be the next United States 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,” Mr. Trump wrote on social media.

“In the interim, Secretary of State Marco Rubio will serve as National Security Advisor, while continuing his strong leadership at the State Department. Together, we will continue to fight tirelessly to Make America, and the World, SAFE AGAIN.”

Mr. Waltz came under searing scrutiny in March after revelations that he added journalist Jeffrey Goldberg to a private text chain on the encrypted messaging app Signal, which was used to discuss planning for a sensitive March 15 military operation against Houthi militants in Yemen. A far-right ally of the President, Laura Loomer, has also targeted Mr. Waltz, telling Mr. Trump in a recent Oval Office conversation that he needs to purge aides who she believes are insufficiently loyal to the “Make America Great Again” agenda.

Mr. Waltz, who served in the House representing Florida for three terms before his elevation to the White House, is the most prominent senior administration official to depart since Mr. Trump returned to the White House. In his second term, the Republican President had been looking to avoid the tumult of his first four years in office, during which he cycled through four national security advisers, four White House chiefs of staff and two secretaries of state.

The Signal chain also showed that Defence Secretary Pete Hegseth provided the exact timings of warplane launches and when bombs would drop. Mr. Waltz had previously taken “full responsibility” for building the message chain and administration officials described the episode as a “mistake” but one that caused Americans no harm. Mr. Waltz maintained that he was not sure how Mr. Goldberg ended up in the messaging chain, and insisted he did not know the journalist.

Mr. Trump and the White House — which insisted that no classified information was shared on the text chain — have stood by Mr. Waltz publicly throughout the episode. But the embattled national security adviser was also under siege from personalities such as Ms. Loomer, who had been complaining to administration officials that she had been excluded from the vetting process for National Security Council aides. In her view, Mr. Waltz relied too much on “neocons” — referring to hawkish neoconservatives within the Republican Party — as well as others who Ms. Loomer argued were “not-MAGA-enough” types.

Mr. Waltz was on television as late as Thursday (May 1, 2025) morning, promoting the administration’s agreement with Kyiv that would allow the U.S. to access Ukraine’s critical minerals and other natural resources. As reports began to circulate that Mr. Waltz could be leaving the administration, Ms. Loomer appeared to take credit in a post on the social media site X, writing: “SCALP.”