A senior Ukrainian official said on Friday that a leak of documents detailing U.S. and NATO efforts to support a possible Ukrainian counteroffensive appeared to be a Russian disinformation operation aimed at creating doubt about Kyiv’s military plans.
The classified war documents, which were posted this week on social media, included a “very large amount of fictitious information,” Mykhailo Podolyak, an adviser to Ukraine’s president, said in an interview with the Reuters news agency.
The New York Times reported on Thursday that the Pentagon was investigating how the war plans were leaked.
On Thursday, before The Times’s article was published, the head of Ukraine’s National Security and Defense Council said that only a handful of people know when or where any counteroffensive would take place.
“When this or that military action, this or that military operation begins, as of today I can tell you with confidence that this is information for a very limited circle of people,” the official, Oleksiy Danilov, said in an interview with Radio Liberty. “When it begins, you will see it all,” he said, adding that “this question is completely closed for today.”
It was not clear whether Mr. Danilov was responding to the leak of the American and NATO documents, which appeared on Twitter and on the Telegram messaging app. But his remarks were in keeping with Ukraine’s practice of disclosing little information about its military plans and using public statements to try to keep Russian forces off-balance.
It was also not clear how or whether the document leak might affect Ukraine’s plans to begin a counteroffensive to take back territory lost to Russia, an operation that American officials have said could begin in the next month or so. The documents do not provide specific battle plans, and because they are five weeks old, they offer only a snapshot of time — the American and Ukrainian view, as of March 1, of what Ukrainian troops might need for the campaign.
Military analysts said the documents appeared to have been modified in certain parts from their original format, overstating American estimates of Ukrainian war dead and understating estimates of Russian troops killed. Analysts said those modifications could point to an effort of disinformation by Moscow.
Still, the disclosures in the leaked documents — which appear as photographs of charts of anticipated weapons deliveries, troop and battalion strengths, and other plans — represent a significant breach of American intelligence in the effort to aid Ukraine. Biden administration officials were working to get them deleted but had not succeeded as of Thursday evening.
The documents mention, for instance, the expenditure rate of HIMARS — American-supplied high-mobility artillery rocket systems that can launch attacks against targets like ammunition dumps, infrastructure and concentrations of troops from a distance. The Pentagon has not said publicly how quickly Ukrainian troops are using the HIMARS munitions; the documents do.
The United States and allies in Europe have provided tanks, rockets, ammunition and training to Ukraine’s armed forces in recent months, one more than a dozen European Union member states have vowed to supply Ukraine with at least one million artillery shells over the next year. Military experts say Ukraine will use the combined aid in the coming battles.
Reports of a troop buildup by both armies east of the Dnipro River in the Zaporizhzhia region of southern Ukraine suggest that Ukraine may be preparing to attack there. At the same time, months of fierce fighting in two regions of eastern Ukraine, Donetsk and Luhansk, may indicate another possible direction of attack.
Since 2014, Moscow has controlled the Ukrainian region of Crimea as well as territory in Donetsk and Luhansk. After launching its full-scale invasion in February last year, it grabbed further territory in southern and eastern Ukraine. The government in Kyiv says its objective is to win back all of its lost land.
