Top national security officials for President Donald Trump, including his defense secretary, texted plans for upcoming military strikes in Yemen to a group chat in a secure messaging app that included the editor-in-chief for The Atlantic, the magazine reported in a story posted online Monday. The National Security Council said the text chain “appears to be authentic.”

The material in the text chain “contained operational details of forthcoming strikes on Iran-backed Houthi-rebels in Yemen, including information about targets, weapons the U.S. would be deploying, and attack sequencing,” editor-in-chief Jeffrey Goldberg reported.

It was not immediately clear if the specifics of the military operation were classified, but they often are and at the least are kept secure to protect service members and operational security. The U.S. has conducted airstrikes against the Houthis since the militant group began targeting commercial and military vessels in the Red Sea in November 2023.

Just two hours after Goldberg received the details of the attack on March 15, the U.S. began launching a series of airstrikes against Houthi targets in Yemen.

The National Security Council is looking into the matter

The National Security Council said in a statement that it was looking into how a journalist’s number was added to the chain in the Signal group chat. In addition to Defense Secretary Pete Hegseth, it included Vice President JD Vance, Secretary of State Marco Rubio and Tulsi Gabbard, Trump’s director of national intelligence.

Goldberg said he received the Signal invitation from Mike Waltz, Trump’s national security adviser, who was also in the group chat.

Hegseth in his first comments on the matter attacked Goldberg as “deceitful” and a “discredited so-called journalist” while alluding to previous critical reporting of Trump from the publication. He did not shed light on why Signal was being used to discuss the sensitive operation or how Goldberg ended up on the message chain.

“Nobody was texting war plans and that’s all I have to say about that,” Hegseth said in an exchange with reporters after landing in Hawaii on Monday as he began his first trip to the Indo-Pacific as defense secretary.

Trump on Tuesday in a brief interview with NBC News’ Garrett Haake downplayed the incident as “the only glitch in two months” of his administration “and it turned out not to be a serious one.”

White House press secretary Karoline Leavitt on Tuesday said in post on X that no war plans were discussed and that “No classified material was sent to the thread.”

Leavitt said on Monday the president still has the “utmost confidence” in Waltz and the national security team. Trump told NBC News on Tuesday that Waltz “has learned a lesson, and he’s a good man.”

Earlier Monday, Trump told reporters: “I don’t know anything about it. You’re telling me about it for the first time.” He added that The Atlantic was “not much of a magazine.”

By early evening, the president jokingly brushed it aside. He amplified a social media posting from Elon Musk spotlighting a conservative satirical news site article with the cutting headline: “4D Chess: Genius Trump Leaks War Plans to ‘The Atlantic’ Where No One Will Ever See Them.”

Government officials have used Signal for organizational correspondence, but it is not classified and can be hacked. Privacy and tech experts say the popular end-to-end encrypted messaging and voice call app is more secure than conventional texting.

Leavitt said the White House counsel’s office has provided guidance to Trump’s top officials on a number platforms to communicate as safely and efficiently as possible.

Reaction poured in quickly

The sharing of sensitive information comes as Hegseth’s office has just announced a crackdown on leaks of sensitive information, including the potential use of polygraphs on defense personnel to determine how reporters have received information.

Sean Parnell, a spokesman for Hegseth, did not immediately respond to requests for comment on why the defense secretary posted operational plans on an unclassified app.

The administration’s handling of the highly sensitive information was swiftly condemned by Democratic lawmakers. Senate Democratic leader Chuck Schumer called for a full investigation.

“This is one of the most stunning breaches of military intelligence I have read about in a very, very long time,” Schumer, a New York Democrat, said in a floor speech Monday afternoon.