The Kremlin dismissed rumors Friday that it ordered the assassination of Wagner chief Yevgeny Prigozhin, who reportedly died in an aviation incident after leading an uprising against Russia's military leadership.

"There is a lot of speculation around the plane crash and the tragic death of the passengers, including Yevgeny Prigozhin," Kremlin spokesman Dmitry Peskov told reporters during a briefing.

"Of course, in the West, this speculation is being presented from a certain angle. All of this is an absolute lie," Peskov said.

The crash on Wednesday occurred exactly two months after Prigozhin led a deadly rebellion against Moscow's top brass. The unrest was seen by observers as having been the biggest threat to President Vladimir Putin's long rule.

After almost 24 hours of silence, Putin on Thursday offered his "sincere condolences to the families of all the victims."

• What we know about the plane crash that reportedly killed Russian Wagner chief Prigozhin and 9 others

He described Prigozhin, once a Kremlin confident and Western sanctioned businessman, as a person who had "made serious mistakes in his life, but he achieved the right results."

The 62-year-old was registered on the plane that was carrying nine others who are also presumed to have died. Prigozhin has yet to be formally identified as among the victims.

"As soon as the results are in, they'll be published," Peskov said.

Asked whether Putin would attend the funeral, the Kremlin's spokesman said a lengthy investigation would need to be completed first.

"The president's work schedule is quite busy at the moment," Peskov said.

A presidential decree signed Friday, two days after Prigozhin's death, stipulates that Russian paramilitary fighters will have to swear an oath to the Russian flag.

The measure is aimed at "forming the spiritual and moral foundations for the defence of the Russian Federation" and... applies to members of volunteer formations — a term usually describing mercenary groups — according to the decree.

It also applies to groups "contributing to the execution of tasks given to the armed forces" and territorial defence units, the decree published on the Kremlin website said.

The U.S. intelligence community is still assessing what caused the plane crash, but there aren't any indications it was a surface-to-air missile, according to the Pentagon.

"Our initial assessment is that it's likely Prigozhin was killed," Air Force Brig. Gen. Patrick Ryder, the Pentagon press secretary, told reporters on Thursday. He said there is no information so far to corroborate press reporting that a surface-to-air missile in Russia brought down the plane.

Another possible cause of the crash U.S. officials are exploring is an explosion onboard the plane, like a bomb.

Prigozhin's first video address since the rebellion attempt appeared just days ago, apparently from Africa, where he said that the Wagner group was making Africa "more free."

Eleanor Watson contributed to this report.

In:
• Wagner Group
• Yevgeny Prigozhin
• Ukraine
• Russia