Secret documents that provide details of US and NATO plans to help prepare Ukraine for a spring offensive against Russia were leaked on Twitter and Telegram, the New York Times reported.
The Pentagon said it is assessing the reported security breach.
“We are aware of the reports of social media posts, and the department is reviewing the matter,” Deputy Press Secretary Sabrina Singh said.
Documents that were at least five weeks old from March 1 contained charts and details about weapons deliveries, battalion strengths and other sensitive information.
One of the documents described the training schedules of 12 Ukraine combat brigades and said nine of them were being trained by US and NATO forces and needed 250 tanks and more than 350 mechanised vehicles.
“To the trained eye of a Russian war planner, field general or intelligence analyst … the documents no doubt offer many tantalizing clues and insights,” the Times said.
Leaked documents a Russian disinformation operation: Ukraine
A Ukrainian presidential official says a leak of classified documents detailing US and NATO plans to help Kyiv looked like a Russian disinformation operation to sow doubts about Ukraine’s planned counteroffensive.
Mykhailo Podolyak told the Reuters news agency that the leaked data reported by The New York Times on Thursday contained a “very large amount of fictitious information” and that Russia was trying to seize back the initiative in its invasion.
“These are just standard elements of operational games by Russian intelligence. And nothing more,” he said in a written statement.
“Russia is looking for any ways to seize back the initiative,” Podolyak said.