Mike Waltz faced questioning from lawmakers for the first time since he was ousted as national security adviser on Tuesday. President Donald Trump has nominated him to be U.S. ambassador to the United Nations, which requires him to be confirmed by the Senate.
Tuesday's hearing provided senators with the first opportunity to grill Waltz over revelations that he added a journalist to a private text chain on the unclassified Signal messaging app that was used to discuss sensitive military plans.
The Atlantic released screenshots of a Signal group chat that involved top Trump officials after the magazine's editor-in-chief, Jeffrey Goldberg, was accidentally added to the conversation.
Although the administration downplayed the chat’s significance, insisting no classified information was shared, the exchange revealed the precise timing of attacks and the assets involved.
The chat, which was set up by Waltz, included Vice President JD Vance, CIA Director John Ratcliffe and about a dozen other top officials. The Trump administration acknowledged that it appeared Goldberg was inadvertently added to the group chat.
Waltz suggested on Tuesday that it was Biden administration officials who recommended he use Signal.
"We followed the recommendation, almost the demand to use, end-to-end encryption, but there was no classified information shared," he said.
He added, "The use of Signal was not only authorized, it's still authorized and highly recommended."
The day after the report emerged, President Donald Trump expressed support for Waltz.
"He's a very good man and he will continue to do a very good job," President Trump said.
Secretary of State Marco Rubio has served in the national security adviser role since May 1, when Waltz left the post.
Dorothy Shea has served as the interim United States ambassador to the United Nations since Jan. 20.
