AP Washington

Top national security officials for US President Donald Trump, including his defence secretary, Pete Hegseth,  texted war 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 on Monday. The National Security Council said the text chain "appears to be authentic". 

Trump initially told reporters he was not aware that the highly sensitive information had been shared, two-and-a-half hours after it was reported. He later appeared to joke about the breach. 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 US 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 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. 

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 Defence Secretary Hegseth, it included Vice-President J D 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 advisor, 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" without offering further explanation. 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. In a statement late on Monday, White House spokeswoman Karoline Leavitt said the President still has the "utmost confidence" in Waltz and the national security team. Earlier on Monday, Trump told reporters, "I don't know anything about it.