Pro-Russian separatists from the Chechen “Death” battalion take part in a training exercise in the territory controlled by the self-proclaimed Donetsk People's Republic, eastern Ukraine, December 8, 2014. Chanting “Allahu Akbar” (God is greatest), dozens of armed men in camouflage uniforms from Russia's republic of Chechnya train in snow in a camp in the rebel-held east Ukraine. They say their “Death” unit fighting Ukrainian forces has 300 people, mostly former state security troops in the mainly-Muslim region where Moscow waged two wars against Islamic insurgents and which is now run by a Kremlin-backed strongman. (Photo by Maxim Shemetov/Reuters)

People take a photograph at the Kremlin, against the backdrop of the Volga river, in the town of Nizhny Novgorod, Russia, July 10, 2015. Russia will host the 2018 FIFA World Cup soccer tournament. (Photo by Maxim Shemetov/Reuters)

A Russian army conscript called up for service in the Kremlin regiment and a woman say farewell at Yekaterinburg-Passazhirsky railway station in Yekaterinburg, Russia on November 15, 2018. (Photo by Donat Sorokin/TASS Russian News Agency)

School leavers celebrate their graduation in Moscow's Red Square in Moscow, Russia on June 20, 2019. (Photo by Artyom Geodakyan/TASS)

Members of the Loktev Ensemble perform during the opening of the 18th Moscow Meets Friends International Festival at the Moscow International House of Music in Moscow, Russia on May 18, 2021. (Photo by Artyom Geodakyan/TASS)

The hair of CSKA Moscow cheerleaders flies high as they perform during the Euroleague Basketball game between Alba Berlin and CSKA Moscow in Moscow, Russia, 04 February 2022. (Photo by Yuri Kochetkov/EPA/EFE)

Russian President Vladimir Putin (R) looks through a window of a research bathyscaphe while submerging into the waters of the Black Sea as he takes part in an expedition near Sevastopol, Crimea, August 18, 2015. (Photo by Alexei Nikolsky/Reuters/RIA Novosti/Kremlin)

A woman looks at model of the Cathedral Mosque in Kazan, during the 28th International Exhibition – Forum of Architecture and Design “Arch Moscow” in Moscow, Russia, 24 May 2023. Arch Moscow is one of the oldest architectural and construction exhibitions in Moscow. The 28th International Exhibition – Forum of Architecture and Design takes place from 24 May to 27 May 2023. (Photo by Yuri Kochetkov/EPA/EFE/Rex Features/Shutterstock)