US Defence Secretary Pete Hegseth shared real-time updates about the planned killing of a Houthi militant in Yemen to a Signal group chat that included a journalist.
Fresh details of the chat between several US officials discussing planned US airstrikes have been published by The Atlantic, whose editor-in-chief Jeffrey Goldberg was added to the group.
The news piles pressure on Donald Trump's administration, which has insisted no US service personnel were put at risk due to the leak of sensitive information.
The messages show Mr Hegseth shared live intelligence about the operation.
At one stage, he texted a timeline of the planned strikes against Houthi rebels, including the line: "Target Terrorist is @ his Known Location so SHOULD BE ON TIME – also, Strike Drones Launch (MQ-9s)".
He said the F-18s would strike the Houthi leader at 1:45pm US eastern time.
White House Press Secretary Karoline Leavitt responded to the latest article by doubling down on attacks on the magazine.
"This entire story was another hoax written by a Trump-hater who is well-known for his sensationalist spin," she wrote on X, adding the White House's position was that the exchanges did not amount to "war plans".
Later that day, Mr Hegseth also posted that the article's author "had never seen a war plan" and accused the media of trying to "peddle hoaxes".
National Security Adviser Mike Waltz, who has accepted responsibility for adding Mr Goldberg in the group chat, also posted that the texts included "no locations" and "no sources & methods".
The revelations have sparked outrage across the political spectrum in the US.
In the newly published article, Mr Goldberg said he believed that the public should see the texts to judge whether there is a security breach after he saw statements by US top officials denying confidential information were included in the group chat.
"These statements presented us with a dilemma," Mr Goldberg wrote.
"There is a clear public interest in disclosing the sort of information that Trump advisers included in non-secure communications channels, especially because senior administration figures are attempting to downplay the significance of the messages that were shared."
US Defence Secretary Pete Hegseth has repeatedly denied sharing military operation plans in the group chat, saying, “Nobody was texting war plans. And that’s all I have to say about that."
The Trump administration also said no classified information was shared in the chat on Tuesday.
According to The Atlantic, Hegseth's text included these details:
“1215et: F-18s LAUNCH (1st strike package)”
“1345: ‘Trigger Based’ F-18 1st Strike Window Starts (Target Terrorist is @ his Known Location so SHOULD BE ON TIME – also, Strike Drones Launch (MQ-9s)”.
Mr Goldberg said his team also contacted the Central Intelligence Agency, the Office of the Director of National Intelligence, the National Security Council, the Department of Defense, and the White House to comment on whether they objected to the news outlet publishing the full texts shared in the chat.
"We wrote, in part: 'In light of statements today from multiple administration officials, including before the Senate Intelligence Committee, that the information in the Signal chain about the Houthi strike is not classified, and that it does not contain ‘war plans,’ The Atlantic is considering publishing the entirety of the Signal chain'," the article reads.
Late Tuesday, the magazine received a response from the White House Press Secretary Karoline Leavitt on email:
“As we have repeatedly stated, there was no classified information transmitted in the group chat. However, as the CIA Director and National Security Advisor have both expressed today, that does not mean we encourage the release of the conversation. This was intended to be a an [sic] internal and private deliberation amongst high-level senior staff and sensitive information was discussed. So for those reason [sic] — yes, we object to the release.”
US National Security Adviser Michael Waltz, who leads the White House's National Security Council, added Mr Goldberg to the Signal group chat, with the embarrassing error triggering widespread concern in Washington about sharing confidential information and using a commercial app to share potentially classified material.
Mr Goldberg said he was added to the chat on March 13, which appeared to include top US officials, including Vice-President JD Vance and Defence Secretary Pete Hegseth.
ABC/Reuters
