The head of Russia’s Wagner mercenary group accused the country’s defense minister and its most senior general of treason on Tuesday, intensifying the most high-profile dispute in the Russian forces since the invasion of Ukraine began.

Wagner’s founder, Yevgeny Prigozhin, who has been taking aim at military leaders in a series of increasingly hostile audio messages on social media this week, accused the “chief of the general staff and minister of defense” of withholding ammunition and supplies from his fighters to try to destroy Wagner, “which can be equated to treason.”

“A bunch of military-related officials have decided that it is their country, that it is their people,” Mr. Prigozhin said in one profanity-laden audio message published by his press service on Tuesday. “They have decided that these people will die when it is convenient to them, when they feel like it.”

Russia’s Defense Ministry denied Mr. Prigozhin’s claims, and raised the stakes by indirectly accusing the Wagner leader of damaging the war effort.

In a statement released on Tuesday night, the Defense Ministry listed the amounts of ammunition and fire cover provided in recent days to “volunteer storm units,” its euphemism for Wagner.

“Attempts to sow rifts in the tight mechanism of cooperation and support among the units of Russian forces are counterproductive and are only aiding the enemy,” the ministry said.

Mr. Prigozhin’s vitriol highlighted the increasingly tense competition for resources among Russian military leaders as the war in Ukraine enters its second year, said Dmitri Kuznets, a military analyst for the independent Russian news outlet Meduza. He said it also showed how the war was reshaping Russian politics.

“Prigozhin is positioning himself as a de facto leader of a faction opposed to the military establishment in Russia’s main political arena, which today is the war,” said Mr. Kuznets.

A native of St. Petersburg, Mr. Prigozhin operated for years in secrecy, using connections forged with Vladimir V. Putin when Mr. Putin worked in that city, to win catering and construction contracts with the government. After making his fortune, he began building up Wagner, using his mercenary force both to expand his businesses and to advance the Kremlin’s political goals in eastern Ukraine, Syria and Africa.

The invasion of Ukraine supercharged his public profile, turning him from a shadow operator into one of the most visible faces of the Kremlin’s military effort. And as the Russian armed forces suffered one humiliating setback after another, Mr. Prigozhin presented Wagner as a bulwark of Russian interests.

In his social media appearances, Mr. Prigozhin offered a stark contrast to the straight-faced Kremlin apparatchiks, appearing in battlefield catacombs, the cockpit of an airborne military jet and Siberian penal colonies.

Swelled with recruits from Russian prisons, Wagner emerged as a capable fighting formation, leading the monthslong assault on the Ukrainian city of Bakhmut, which has become the focal battle of the war. Wagner has gradually tightened its grip on the city in recent weeks by overrunning surrounding villages in a series of costly frontal assaults.

Wagner’s gains around Bakhmut have made it the only Russian force to make meaningful progress since offensive operations were revved up this month. That probably stoked jealousy from the military command, Mr. Kuznets said.

But Mr. Prigozhin’s growing self-promotion and disdain for bureaucracy have begun to cause concern among some Kremlin insiders. Some see in his social media performances a hint of political ambition.

Now, Mr. Prigozhin’s long-running criticism of the military hierarchy, once oblique, has taken on an aggressive, even desperate tone, just as the battle for Bakhmut appears to be entering a critical phase. Explaining his decision to go public with his accusations against the military commanders, Mr. Prigozhin in one audio message said, “I don’t have an option, I’m going until the end.”

“My people are dying in heaps,” he said.

Mr. Prigozhin accused the Russian defense minister, Sergei K. Shoigu, and the chief of the general staff, Valery V. Gerasimov, of deliberately starving Wagner of supplies, using their titles but not directly naming the two men.

The accusations came days after Mr. Prigozhin said the defense ministry had banned him from recruiting new fighters from Russian jails to “bleed out” Wagner and deny it victory in Bakhmut.

Since last summer, Wagner has recruited tens of thousands of convicts by securing a presidential pardon for the enlisted men, a campaign that appeared to show the extent of Mr. Prigozhin’s influence with Mr. Putin.

But this week’s audio messages suggest that his access to the Russian leader may be waning, some analysts said.

“This is an act of desperation,” one political scientist, Tatiana Stanovaya, wrote on the Telegram messaging app on Monday. “It’s an attempt to reach Putin through publicity, to scare the military command with political consequences.”

Mr. Prigozhin said Monday that he had not had problems with ammunition under the last commander of Russian forces in Ukraine, Gen. Sergei Surovikin, referring to him by name. General Surovikin was replaced by General Gerasimov last month.

Some analysts have interpreted the appointment of General Gerasimov, who holds a position equivalent to the chairman of the Joint Chiefs of Staff in the United States, as an attempt to improve coordination between Russia’s fighting forces ahead of a spring offensive.

Even as Mr. Prigozhin escalated his attacks on the military command, he appeared to be trying to shore up alliances with other paramilitary leaders who could be affected by the shake-up of the Russian military. In recent days, he has posted photos and videos with Apti Alaudinov, commander of pro-Kremlin Chechen fighters in Ukraine, and Eduard Basurin, a former commander of a pro-Russian militia in the Donbas region of eastern Ukraine.

Mr. Alaudinov’s boss, the Chechen strongman Ramzan Kadyrov, has also criticized the wartime performance of Russian generals. And prominent Russian military bloggers said last week that Mr. Basurin had fallen victim to Moscow’s recent purge of Donbas separatist officers.

Mr. Prigozhin’s caustic audio messages were especially remarkable given that they were released just before Mr. Putin made his state of the nation address in Moscow, in which he called for unity in a war that he falsely said had been caused by Western aggression.

Mr. Prigozhin did not appear to be among the dozens of military leaders and decorated soldiers present for the address, and Mr. Putin did not mention Wagner during his lengthy praise of the Russian military in Ukraine. Mr. Putin said he had chosen to omit the names of various “volunteer” units from his speech.

“I was afraid of upsetting those whom I would not mention,” he said.

When asked by a journalist to comment on the speech, Mr. Prigozhin said he had been too busy to watch it, a response that played into his image as a maverick.

Ms. Stanovaya said the public tensions between Wagner and the defense ministry were unlikely to be well received by the Russian president, who has made obedience and coordination between subordinates a cornerstone of his rule.

“I can say with almost 100 percent certainty that all of these clashes, this infighting, are infuriating” Mr. Putin, she wrote.

But Mr. Prigozhin appeared to be far from backing down. He called the defense ministry’s response to his complaints “a spit in the direction of PMC Wagner and an attempt to hide their crimes against those fighters.”

Thomas Gibbons-Neff contributed reporting.