The founder of Russia's Wagner mercenary force has said his troops now tightening their grip on the Ukrainian city of Bakhmut are being deprived of ammunition and that, if they are forced to retreat, the entire front will collapse.
Yevgeny Prigozhin had said on Friday that his units had "practically surrounded Bakhmut", where fighting has intensified in the past week after months of attritional warfare, with Russian forces attacking from three sides.
Wagner often appears to operate autonomously from the regular army, or even in competition with it - and in a video published over the weekend, Prigozhin complained that the ammunition that Moscow had promised it had not been delivered.
"If Wagner retreats from Bakhmut now, the whole front will collapse," Prigozhin said. "The situation will not be sweet for all military formations protecting Russian interests."
Reuters could not independently verify when and where the video was recorded. It was published not on Prigozhin's usual press service Telegram channel, but on one that has associated itself with Wagner and disseminated news about Prigozhin.
On his usual channel, Prigozhin also mentioned the lack of ammunition, saying on Sunday: "For now, we are trying to figure out the reason: Is it just ordinary bureaucracy, or a betrayal?"
Prigozhin regularly criticizes the military hierarchy and last month accused Defence Minister Sergei Shoigu and others of "treason" for withholding munitions.
A prominent opponent of Prigozhin's, Russian nationalist ex-rebel commander Igor Girkin, said without citing evidence that the doom-laden video published at the weekend had been recorded at the height of that row, about two weeks ago.
In the nearly four-minute video published on the Wagner Orchestra Telegram channel on Saturday, Prigozhin said his troops were worried that Moscow wanted to set them up as potential scapegoats if Russia lost the war.
"If we retreat, then we will go down in history forever as people who have taken the main step towards losing the war," he said.
"This is exactly the problem with 'ammunition hunger'."
Prigozhin delivered his sometimes repetitive monolog in what appeared to be a bunker, with a dim light casting his heavy shadow on the wall behind him.
He said his troops would wonder whether they were being "set up" for defeat by the top brass or even someone "higher."
Prigozhin has used the war to become a public figure in Russia, and strong signs have emerged in the past month that the Kremlin wants to clip his wings after he began feuding with the defense establishment.
The Defence Ministry said last month it was "absolutely untrue" that Wagner was being starved of ammunition.
Fall of Bakhmut would not mean Russia has changed tide of war - Pentagon chief
US Defense Secretary Lloyd Austin said on Monday that the eastern Ukrainian city of Bakhmut was of more symbolic than operational importance, and its fall would not necessarily mean that Moscow had regained the initiative in the war.
The battle for Bakhmut has raged for seven months. A Russian victory in the city, which had a pre-war population of about 70,000 but has now been blasted to ruins, would give Moscow the first major prize in a costly winter offensive.
"I think it is more of a symbolic value than it is strategic and operational value," Austin told reporters while visiting Jordan.
"The fall of Bakhmut won't necessarily mean that the Russians have changed the tide of this fight," he said, adding that he would not predict whether or when Bakhmut might fall.
Russian artillery have been pounding the last routes out of the city, aiming to complete its encirclement, but the founder of the Wagner mercenary force leading the assault has said his troops are being deprived of ammunition by Moscow.
Austin said that if Ukrainian forces decided to reposition west of Bakhmut, he would not view that as a strategic setback.
Wagner often appears to operate autonomously from the regular army, or even in competition with it - and in a video published over the weekend, Prigozhin complained that the ammunition that Moscow had promised it had not been delivered.
Prigozhin regularly criticizes the military hierarchy and last month accused Defence Minister Sergei Shoigu and others of "treason" for withholding munitions.
Austin alluded to differences between Wagner and the military, saying: "I think the fissures are there ...
"I would say the Wagner forces have been a bit more effective than the Russian forces ... Having said that, we have not seen exemplary performance from Russian forces."