- Bernd Debussmann Jr. and Chris Partridge
- BBC News
The Pentagon said the leak of classified US Department of Defense documents poses an “extremely serious” risk to national security.
The documents appear to contain sensitive information related to the war in Ukraine, as well as about China and US allies.
Officials say the leaked files were in a format similar to documents issued to senior commanders.
An investigation has been launched to determine the source of the leak.
The documents, some of which officials say may have been modified, first appeared on online platforms such as Twitter, 4chan and Telegram, as well as on the Discord server of the video game Minecraft.
In addition to highly detailed information about the war in Ukraine, some of the leaked documents are said to shed light on sensitive briefing materials related to US allies.
Reports said other documents focus on defense and security issues in the Middle East as well as in the Indo-Pacific region.
Speaking to reporters Monday, a senior Pentagon official said the documents “pose a very serious national security risk and have the potential to spread disinformation.”
“We’re still investigating how this happened, as well as the scope of the case,” said Chris Meagher, Assistant Secretary of Defense for Public Affairs.
“There have been steps to take a closer look at how and to whom this type of information is distributed,” he added.
Meagher declined to answer when asked if the Pentagon believed the documents were authentic, though he said some of them “appear to have been altered.”
The Justice Department is now investigating the leak, along with officials from the Pentagon, the White House and elsewhere in the US government.
The format of the documents, Meagher added, is similar to those “used to provide daily updates to our senior leaders on Ukraine and Russia-related operations, as well as other intelligence updates.”
He said the Pentagon first became aware of the leaked documents last week, with Defense Secretary Lloyd Austin first briefed on the matter on April 6.
Meagher said the leak of the documents prompted US officials to reassure allies “of our commitment to protecting intelligence and fidelity to our security partnerships.”
In a separate briefing, national security spokesman John Kirby said US President Joe Biden first learned of the leak last week.
When asked if the leak had been contained so far and if there were other documents not yet disclosed, Kirby said, “I don’t know.”
BBC News has so far reviewed more than 20 documents, many of which appear to detail the deployment of Ukrainian and Russian forces and their condition ahead of the long-awaited spring offensive by Ukrainian forces.
Some of the documents appear to, for example, specify US training and equipment being provided to Ukraine prior to the attack, as well as when the various Ukrainian units will be ready and the expected delivery time for military supplies.
While Meagher declined to comment on the potential impact the documents could have on the front lines in Ukraine, he said that “the Ukrainians have shown their ability and competence in this war.”
“Both the president and the Secretary of Defense have made it clear that the United States will be with them no matter how long it takes,” he said.