Chris Meagher, assistant to the secretary of defense for public affairs, told reporters that Defense Secretary Lloyd Austin first became aware on Thursday that a number of classified briefing slides detailing the U.S. military efforts in the Ukraine War and intelligence involving other nations were leaked.
The department is looking closely at “how this type of information is distributed and to whom,” Meagher said.
At the White House, National Security Council spokesman John Kirby was asked if the U.S. was bracing for more online releases.
“The truth and the honest answer to your question is: We don’t know," he said. "And is that a matter of concern to us? You’re darn right it is.”
Kirby said at this point, “we don't know who’s behind this, we don’t know what the motive is.”
And he said as U.S. authorities go through the documents that were posted online, they are still trying to determine their validity, but have found that at least some of the papers "have been doctored.”
He and others would not go into detail, but at least one of the documents shows estimates of Russian troops deaths in the Ukraine war that are significantly lower than numbers publicly stated by U.S. officials. Under a section titled “Total Assessed Losses,” one document lists 16,000-17,500 Russian casualties and up to 71,000 Ukrainian casualties.
Investigators who specialize in tracking social media, including at the journalism organization Bellingcat, say the documents may have been circulating for months in private internet chats on the Discord discussion platform.
Asked if the Pentagon has contacted Discord, Meagher referred questions to the Justice Department, which has opened a criminal investigation into the leaks.
While the Pentagon has been careful not to authenticate the information contained in any specific document, overall "they present a very serious risk to national security and have the potential to spread disinformation,” said Meagher.