The Atlantic's magazine's editor-in-chief Jeffrey Goldberg said in a report on Monday that he was inadvertently invited on March 13 to an encrypted chat group on the Signal messaging app called the "Houthi PC small group".
In the group, national security adviser Mike Waltz tasked his deputy Alex Wong with setting up a "tiger team" to co-ordinate US action against the Houthis.
The US 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 US began launching a series of airstrikes against Houthi targets in Yemen.
Hours before those attacks started, Hegseth posted operational details about the plan, "including information about targets, weapons the US would be deploying, and attack sequencing," Goldberg said, declining to disclose the details of what he termed the "shockingly reckless" use of the Signal chat to co-ordinate the strike.
The information leak comes as Hegseth's office has just announced a crackdown on leaks of sensitive information, including the potential use of polygraphs on defence personnel to determine how reporters have received information.
The Defense Department referred a Reuters request for comment to the National Security Council, and NSC spokesman Brian Hughes said the chat group appeared to be authentic.
"At this time, the message thread that was reported appears to be authentic, and we are reviewing how an inadvertent number was added to the chain," he said.
"The thread is a demonstration of the deep and thoughtful policy co-ordination between senior officials. The ongoing success of the Houthi operation demonstrates that there were no threats to our servicemembers or our national security," Hughes said.
with AP
