Russian military leaders were aware of Prigozhin's mutiny plan: US officials

The United States assesses that members of Russia's military leadership were aware of Yevgeny Prigozhin's planned mutiny before he marched on Moscow, according to Biden administration officials.

One senior official told ABC News' Martha Raddatz that General Sergei Surovikin, who was previously Russia's top commander in Ukraine, and others had conversations with Prigozhin before he instructed his paramilitary group to storm the capital city, resulting in the greatest threat to Russian President Vladimir Putin since he came into power more than two decades ago.

Nicknamed "General Armageddon," Surovikin is known to have had a close relationship with Prigozhin in the past. He was also one of the first high-ranking Russian officials to call on Prigozhin to abandon his march in a video message posted on Friday.

The U.S. believes that Prigozhin thought some among the top brass would join his cause although they ultimately did not, and now Putin wants to investigate possible coordination between his military and the mercenary leader, the official added.

But Putin's desire to carry out such a probe may be overshadowed by his need to project strength and unity among Russia's top ranks during the precarious time.

The Kremlin has been trying to downplay the risk Putin faced last weekend, and while the Russian president has said little in the wake of the uprising -- giving only brief televised remarks on Monday evening -- his ardent ally Belarussian President Alexander Lukashenko has been enlisted as a de facto spokesperson.

Lukashenko, who purportedly brokered the deal that abruptly ended the mutiny and is currently playing host to Prigozhin, also claimed he talked Putin out of killing his former friend.

Sources within the administration say that U.S. intelligence assesses that the Kremlin instructed Lukashenko to emphasize Putin's initial inclination to kill Prigozhin in an attempt to perpetuate Putin's image as a strongman.

Prigozhin used a false pretext to lead his forces in an armed insurrection against the Russian state, claiming that his forces had been bombed to justify actions against Russian Defense Minister Sergei Shoigu and Russian defense leaders, according to one senior U.S. official.

Prigozhin is surrounded by his own security force, which is comprised of Wagner mercenaries, and is said to be in a "forlorn" and "uncertain" mood, a U.S. official said.

Publicly, leaders in Washington have sought to walk a fine line in the wake of the revolt, declining to even characterize Prigozhin's march on Moscow, which saw his fighters temporarily overtake Russian military facilities and come within a hundred miles of the city while facing limited opposition.

President Joe Biden said on Wednesday that Putin had "absolutely" been weakened by Prigozhin's challenge, but to what extent was "hard to tell."

A White House spokesperson also declined to say whether the White House believed top Russian military leaders had advanced knowledge of Prigozhin's mutiny, calling it "an internal matter in Russia."

At an event in New York, Secretary of State Antony Blinken was also asked about the latest developments involving Prigozhin and Moscow, where he predicted there would be more fallout to come.

"This is a moving picture, and I don't think we've seen the last act," Blinken said. "We have to have a certain amount of humility in any predictions we make."

ABC News' Ian Pannell, Molly Nagle and Ben Gittleson contributed to this report.