Washington DC - The White House on Monday confirmed that a journalist was accidentally included in a group chat in which US Defense Secretary Pete Hegseth and other top officials discussed upcoming strikes against Yemen's Houthi rebels.

President Donald Trump had announced strikes on March 15, but in a shocking security breach, The Atlantic magazine's editor-in-chief Jeffrey Goldberg wrote that he had hours of advance notice via the group chat on Signal.

"The message thread that was reported appears to be authentic, and we are reviewing how an inadvertent number was added to the chain," National Security Council spokesman Brian Hughes said.

Goldberg did not provide details of the plan but wrote that Hegseth sent information on the strikes, including "targets, weapons the US would be deploying, and attack sequencing," to the group chat.

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"According to the lengthy Hegseth text, the first detonations in Yemen would be felt two hours hence, at 1:45 pm eastern time," Goldberg wrote – a timeline that was borne out on the ground in Yemen.

Goldberg said he was added to the group chat two days earlier and received messages from other top government officials designating representatives who would work on the issue.

On March 14, a person identified as Vice President JD Vance expressed doubts about carrying out the strikes, saying he hated "bailing Europe out again," as countries there were more affected by Houthi attacks on shipping than the US.

Group chat contributors identified as National Security Advisor Mike Waltz and Hegseth both sent messages arguing only Washington had the capability to carry out the mission, with the latter official noting that he shared Vance's "loathing of European free-loading."

And a person identified as "S M" – possibly Trump adviser Stephen Miller – argued that "if the US successfully restores freedom of navigation at great cost there needs to be some further economic gain extracted in return."

Trump told journalists, "I don't know anything about it. You're telling me about it for the first time." He added that his recent attacks on the Houthis have been "very effective" in any case.