Vladimir Putin is now left with the stark option of either agreeing to end the conflict in Ukraine on the terms of the U.S. or up the ante by using more lethal weaponry, the president's former spokesperson said.

Sergei Markov said that Putin remains very popular among elite sections of Russian society despite the abandoned rebellion by Wagner mercenaries as they headed for Moscow.

He also shed some light on why the Wagner soldiers were not met by more resistance in Russia and he said it was because they are treated like "heroes" for fighting for the country in Ukraine.

The Wagner mercenaries returned to their base after Putin accepted an amnesty deal which meant their leader would go into exile.