Washington, United States — The White House on Monday confirmed that a journalist was included in a group chat in which US Defense Secretary Pete Hegseth and other top officials discussed upcoming strikes against Yemen's Huthi rebels.

President Donald Trump announced strikes on 15 March, 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 on "targets, weapons the US would be deploying, and attack sequencing," to the group chat.

"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 14 March, 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 Huthi attacks on shipping than the United States.

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."

The Huthi rebels, who have controlled much of Yemen for more than a decade, are part of the "axis of resistance" of pro-Iran groups staunchly opposed to Israel and the United States.

They have launched scores of drone and missiles attacks at ships passing Yemen in the Red Sea and Gulf of Aden during the Gaza war, claiming solidarity with the Palestinians.