The documents, which carry US Joint Chiefs of Staff seals and allegedly belong to the US and NATO, were shared on Twitter and Telegram.
The Defense Department is "aware of the reports of social media posts, and the Department is reviewing the matter," Deputy Pentagon spokeswoman Sabrina Singh told Anadolu.
Singh did not specify if the documents and their contents are authentic.
Documents include Ukrainian army's training, aid calendars
The documents include details such as analyses about the course of the war, humanitarian aid provided by different countries and calendars for aid being transmitted on the ground.
They do not show specific times and places of war but contain factual information about the requirements of the Ukrainian army for the following weeks.
On documents marked "top secret," there are details about the Ukrainian battalion locations and sizes, as well as total losses on both sides.
A document listing the Ukrainian military equipment and training process suggests that 12 battalions have been prepared, and nine were trained by NATO allies and the US.
The same document reveals that six of the nine battalions will be ready by March 31 and the rest by April 30. The nine will need up to 250 tanks and 350 mechanized vehicles.
Some contents allegedly altered

Although the documents are largely believed to be factual, some contents were allegedly altered.
Losses for Ukraine are shown as more than what it is, while losses for Russia are minimized, according to military analysts.
Between 16,000 and 17,500 Russian soldiers have been killed, while Ukrainian losses are more than 71,500, according to one document.
But there are at least 200,000 deaths and casualties on the Russian side, while losses for Ukraine are more than 100,000, according to US sources.