Cracks are starting to show among Russian fighters as Wagner's chief called out the "treachery" or "bureacracy" of Moscow officials for failing to supply his troops.
Yevgeny Prigozhin's soldiers have joined the regular Russian army as they battle Ukrainian forces to capture Bakhmut, an eastern city that has become the frontline of the current conflict.
But Prigozhin has publicly called out the Kremlin amid tense relations between Wagner and Moscow.
In a post on Sunday, Prigozhin said he expected ammunition to arrive to resupply his forces on February 23 that never emerged.
Prigozhin suggested it could have been deliberate, blaming it on "ordinary bureaucracy or a betrayal".
In a separate video posted Saturday, which might have been filmed earlier in February, Prigozhin moaned about how his men feared they were being "set up" as scapegoats in case they get defeated.
"If we step back, we will go down in history as the people who took the main step to lose the war," he said.
"And this is precisely the problem with the shell hunger [ammunition shortage]. This is not my opinion, but that of ordinary fighters...
"What if they [the Russian authorities] want to set us up, saying that we are scoundrels - and that's why they are not giving us ammunition, not giving us weapons, and not letting us replenish our personnel, including [recruiting] prisoners?"
The shadowy Wagner group - which has been likened to Vladimir Putin's private army and thought to be responsible for atrocities across the globe - has tens of thousands of troops stationed in Ukraine.
Many of them were recruited directly from Russia's prisons and penal colonies.
Pressure from Russian forces continues to mount in Bakhmut with residents trying to flee with help from troops over the weekend.
Western analysts say Ukrainian troops may be preparing to withdraw from the key eastern stronghold.
A woman was killed and two men were badly wounded by shelling while trying to cross a makeshift bridge out of the city in Donetsk province, according to Ukrainian troops who were assisting them.
A Ukrainian army representative who asked not to be named for operational reasons told The Associated Press that it was now too dangerous for civilians to leave Bakhmut by vehicle and that people had to flee on foot instead.
Bakhmut has for months been a prime target of Moscow's grinding eastern offensive in the war, with Russian troops, including forces from the private Wagner Group, inching ever closer.
The Institute for the Study of War, a Washington-based think tank, assessed late on Friday that Kyiv's actions may point to a looming pullout from parts of the city.
It said Ukrainian troops may "conduct a limited and controlled withdrawal from particularly difficult sections of eastern Bakhmut," while seeking to inhibit Russian movement there and limit exit routes to the west.
Capturing Bakhmut would not only give Russian fighters a rare battlefield gain after months of setbacks, but it might rupture Ukraine's supply lines and allow the Kremlin's forces to press toward other Ukrainian strongholds in the Donetsk region.
