US Defense Secretary Lloyd Austin on Thursday praised the “swift arrest” of the alleged source of secret documents and pledged to review intelligence-sharing procedures in response, indirectly confirming the leaked documents were authentic.

Austin said he had directed his deputy for intelligence and security to “conduct a review of our intelligence access, accountability and control procedures within the Department to inform our efforts to prevent this kind of incident from happening again.”

The Pentagon will work with the US intelligence community to “review the national security implications of this unauthorized disclosure,” Austin said, thanking the Disclosures Task Force for “working around the clock to assess and mitigate any damage done.”

Austin concluded by reminding every Pentagon employee, military or civilian, that they have “a solemn legal and moral obligation to safeguard” classified information and report “any suspicious activity or behavior.”

A 21-year-old airman in the Massachusetts Air National Guard was arrested by the FBI on Thursday, after being identified by the New York Times and an employee of the “open source intelligence” outfit Bellingcat. He allegedly took photos of secret and top-secret presentation slides intended for the Joint Chiefs and shared them with gamer friends on the messaging platform Discord.

The documents, which eventually found their way to the wider public, initially related to the Ukraine conflict. Later batches contained reports about Israel, South Korea, Serbia and China – almost all of which have been officially denied as false, fabricated or otherwise inaccurate. Ukraine denounced the leaks as Russian disinformation, while Russia said they could be an American psyop.