In this undated photo released Tuesday April 13, 2021, by Russian Defense Ministry Press Service, A Tu-160 strategic bomber of the Russian air force is shown on a training mission somewhere in Russia. Russian Defense Minister Sergei Shoigu on Tuesday described a massive military buildup in western Russia as part of drills intended to check the armed forces' readiness amid the threats posed by NATO. (Photo by Vadim Savitsky/Russian Defense Ministry Press Service via AP Photo)

Members of an Orthodox community take part in an Easter service at a church in the village of Poteryaevka, some 200 km (124 miles) southwest of the city of Barnaul in Russia's Altai region, on April 24, 2011. (Reuters/Andrei Kasprishin)

Russia's Maria Stavitskaia performs during the ladies short program at the Rostelecom Cup ISU Grand Prix of Figure Skating in Moscow November 14, 2014. (Photo by Grigory Dukor/Reuters)

Michal Navratil of the Czech Republic performs after the men's 27 meter high dive final at the Swimming World Championships in Kazan, Russia, Wednesday, August 5, 2015. (Photo by Denis Tyrin/AP Photo)

Shell, which is the replica of the biggest detonated Soviet nuclear bomb AN-602 (Tsar-Bomb), is on display in Moscow, Russia, August 31, 2015. The shell is part of an exhibition organized by the state nuclear corporation Rosatom. (Photo by Maxim Zmeyev/Reuters)

Seals dressed in military uniforms swim during a show marking the 70th anniversary of the end of World War Two, at an aquatic park in the Siberian city of Irkutsk, Russia, May 9, 2015. (Photo by Evgeny Kozyrev/Reuters)

A woman takes a dip in a font on the eve of the Orthodox Epiphany in central Moscow, Russia, January 18, 2016. Orthodox believers mark Epiphany on January 19 by immersing themselves in icy waters regardless of the weather. (Photo by Sergei Karpukhin/Reuters)

A participant performs during the Perfect Pole 2016 pole dance championship in the southern city of Stavropol, Russia, October 22, 2016. (Photo by Eduard Korniyenko/Reuters)