Hegseth could have endangered troop safety with Signal chat - Pentagon watchdog

US Defence Secretary Pete Hegseth could have endangered troops' safety when he used an unsecured app to discuss a planned attack on militants in Yemen, according to a report from the Pentagon's inspector general, an internal watchdog.

The details of the March attack were discussed on the commercial Signal app, and were first revealed after a journalist was mistakenly added to the group chat.

Using his personal device, Hegseth shared information from a classified report, but the inspector general noted that the secretary has authority to determine classification.

The inspector general's office released an unredated copy of the report on Thursday.

The inspector general (IG) found Hegseth had acted against Pentagon policy when he used the unsecured messaging app, as well as his personal device, to transmit sensitive information about an air attack on Houthi fighters before it had taken place.

"Using a personal cell phone to conduct official business and send nonpublic Department of Defence information through Signal risks potential compromise of sensitive DoD information, which could cause harm to the DoD personnel and mission objectives," the report stated.

The Signal chat was revealed by the Atlantic magazine, after its editor-in-chief was accidentally added by then-National Security Adviser Mike Waltz.

It showed Hegseth discussing specific targets, and timings for attacks, as well as the types of weapons that would be used.

The information had been derived from a classified email which was labelled "SECRET//NOFORN" - meaning that its contents were secret, it could harm national security if it was released, and that it should not be viewed by any foreign national.

According to the IG report, the Pentagon only received a partial copy of the messages from Hegeth's personal cell phone.

The inspector general there had to "rely in-part on the transcript the Atlantic posted publicly...for a full record."

The Trump administration has denied the information shared in the chat was classified. The inspector general did not determine whether Hegseth had made the decision to formally declassify it, which he has the power to do, before posting it.

Responding to the report, Hegseth posted on X: "No classified information. Total exoneration. Case closed. Houthis bombed into submission."

"Thank you for your attention to this IG report," he wrote to end the post, echoing how President Donald Trump frequently ends his social media posts.

The investigation was requested by the Republican-led Senate Armed Services Committee.

Most major departments in the US government have inspector generals, independent officials who conduct audits and investigations.

Hegseth declined to sit for an interview with the inspector general's office, and instead submitted a written statement.

A spokesman for the Pentagon said the report is "a total exoneration of Secretary Hegseth and proves what we knew all along - no classified information was shared."

White House Press Secretary Karoline Leavitt said that the report proves "no classified information was leaked, and operational security was not compromised".

But Senator Mark Warner, the top Democrat on the Senate Intelligence Committee, called for Hegseth to resign after the report was delivered to Congress.

"An objective, evidence-based investigation by the Pentagon's internal watchdog leaves no doubt: Secretary Hegseth endangered the lives of American pilots," Warner said in a statement.

He also said the report found Hegseth had used Signal to set up other unsecured chats, "underscoring that this was not an isolated lapse. It reflects a broader pattern of recklessness and poor judgement from a secretary who has repeatedly shown he is in over his head."

Hegseth, who heads a military of more than 1 million service members, has been under scrutiny recently for overseeing a US attack on a boat carrying suspected drug traffickers.

He denies reports that he instructed troops to "kill all" of the suspects on the boat, and says he was not aware that there were survivors killed in a second airstrike on the target.