The highly classified leaked Pentagon documents posted to social media offer a pessimistic US viewpoint about the state of the war in Ukraine, highlighting weaknesses in Ukraine’s weaponry and air defenses and predicting a stalemate in the war for months to come.

The documents, which appear to date from February and March, detail many of Ukraine’s perceived military shortfalls as Kyiv prepares for a spring counteroffensive against Russia.

Several of the classified documents warn that Ukraine’s medium-range air defenses to protect front-line troops will be “completely reduced by May 23,” suggesting Russia could soon have aerial superiority and Ukraine could lose the ability to amass ground forces in a counteroffensive.

The documents also underscore lingering problems with Russia’s own military offensive, predicting that the result will be a stalemate between the two sides for the foreseeable future.

“Russia’s grinding campaign of attrition in the Donbas region is likely heading toward a stalemate, thwarting Mosco’s goal to capture the entire region in 2023,” states one of the classified documents.

Officials familiar with the situation tell CNN the documents appear to be part of a daily intelligence briefing deck prepared for the Pentagon’s senior leaders, including Chairman of the Joint Chiefs of Staff Gen. Mark Milley.

The leaking of the documents, many of which are marked top secret, represents a major national security breach, and the Justice Department has launched a criminal investigation into who may have leaked them while the Pentagon is investigating how the leak impacts US national security. In addition to the assessment of the Ukraine war, the documents include intelligence gathered on allies and adversaries alike.

Retired Lt. Gen. Mark Hertling, a CNN national security and military analyst, said that the challenges Ukraine faces with its planned counteroffensive have been clear for weeks, including the need to integrate new equipment and new troops and ensure that a sufficient supply chain is in place. He did not think that the document leak would alter Kyiv’s plans.

“I haven’t seen anything in the documents I’ve seen that would cause me as a commander to change my plans,” Hertling said. “It’s given some information to the Russians in terms of unit locations and ammo and equipment capabilities, but I would venture to say the Russians already knew all that anyway.”

In many ways, the assessment of the Ukraine war is similar to what US officials have said publicly, as top Biden administration officials have said the conflict is likely to drag on for months, if not longer.

But the detailed and unflinching assessment of the war is laid out starkly in the briefing slides about the challenges Ukraine faces despite its successes more than a year into the war.

An official from a country part of the Five Eyes intelligence-sharing agreement with the US told CNN previously that it was alarming to see the leaked Ukraine war information handicapping the country on the battlefield.