Pentagon says leaked documents a 'very serious' risk to security

American intelligence seems baffled over leaks of top secret Pentagon information, ITV News' Correspondent Robert Moore explains how damaging this could be to the US

Online leaks of highly classified US intelligence documents about the Ukraine war present a "very serious" risk to national security, the Pentagon has said.

Last week, leaks began to emerge on social media sites, including Twitter, of US training and equipment schedules to support Ukraine, assessments of losses, what Washington is monitoring on key allies and strategic partners, and what moves Russia may be taking to undermine those relationships.

Chris Meagher, assistant to the secretary of defence for public affairs, told reporters that 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".

He added Defence Secretary Lloyd Austin first became aware of the developments last Thursday.

In the days since, Mr Austin has reached out to allies and held daily meetings to assess the damage.

He has also set up a group to assess the scope of the information lost and review who has access to briefings in question.

Speaking at the White House, National Security Council spokesman John Kirby was asked if Washington 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."

"We don't know who's behind this, we don't know what the motive is," he added.

US Secretary of Defence Lloyd Austin has held daily talks with allied nations since the leaks first emerged. Credit: AP

Mr Kirby said as US authorities continue to determine the validity of the classified files they found at least some "have been doctored".

One of the documents shows estimates of Russian troops deaths in the Ukraine war, which are significantly lower than numbers publicly stated by US officials.

Under a section titled "Total Assessed Losses" one document lists 16,000-17,500 Russian casualties and up to 71,000 Ukrainian casualties.

General Mark Milley, chairman of the Joint Chiefs of Staff, said last November Russia has lost "well over" 100,000 soldiers, adding that Ukraine had lost around the same number.

Investigators who specialise in tracking social media, including at the journalism organisation Bellingcat, have said the documents may have been circulating for months in private internet chats, on the Discord discussion platform.

Want a quick and expert briefing on the biggest news stories? Listen to our latest podcasts to find out What You Need To Know