WASHINGTON (AP) — Defense Secretary Pete Hegseth put U.S. troops at risk by sharing sensitive plans about an upcoming military strike in Yemen on his personal phone, according to a Pentagon inspector general's report made public Thursday that criticized the use of unapproved messaging apps and devices across the Defense Department.

Hegseth had the authority to declassify the material he shared with others in a Signal chat, the watchdog found. But the release of details about the strike on Houthi militants violated internal Pentagon rules about handling sensitive information that could put service members or their missions in danger.

The report noted that the information that Hegseth sent — the quantity and strike times of manned U.S. aircraft over hostile territory about two hours to four hours before those strikes — “created a risk to operational security that could have resulted in failed U.S. mission objectives and potential harm to U.S. pilots.”

“If this information had fallen into the hands of U.S. adversaries, Houthi forces might have been able to counter U.S. forces or reposition personnel and assets to avoid planned U.S. strikes,” the report said.

Hegseth’s use of the app came to light when a journalist, Jeffrey Goldberg of The Atlantic, was inadvertently added to a Signal text chain by then-national security adviser Mike Waltz.

The report's nuanced findings — that Hegseth's actions put troops at risk but that he had the right to declassify the material — are not likely to relieve the pressure on the former Fox News Channel host. He also is facing scrutiny on Capitol Hill over a report that a follow-up strike on an alleged drug-smuggling boat in the Caribbean Sea in September killed survivors after Hegseth issued a verbal order to “kill everybody.”

Hegseth wrote on social media about the inspector general's report: "No classified information. Total exoneration. Case closed. Houthis bombed into submission."

He had declined to be interviewed for the review. In a one-page statement to the inspector general, Hegseth said he had the authority to declassify the information he was sharing on Signal and that there “was nothing classified in this text.”

“There were no locations or targets identified,” he wrote. “There were no details that would endanger our troops or the mission.”

Hegseth's letter said he was only sharing “an unclassified summary” of operations and that the full details of what was happening were shared separately on a secure network used by the military.

The information he shared on Signal was limited to the “overt actions” of U.S. forces, which he said “would be readily apparent to any observer in the area.”

But the revelations drew intense scrutiny, with Democratic lawmakers and a small number of Republicans saying Hegseth's posting of the information to the Signal chats before the military jets had reached their targets potentially put those pilots’ lives at risk.

Lawmakers also noted that if lower-ranking members of the military had acted similarly, they would have been fired or severely disciplined for failing to maintain operational security.