Military helicopters fly over the Red Square during a rehearsal for the Victory Day parade in Moscow, Russia, May 7, 2019. The 74th anniversary of the victory over Nazi Germany in World War II will be marked here on May 9. (Xinhua/Bai Xueqi)

Self-propelled howitzers roll down the Red Square during a rehearsal for the Victory Day parade in Moscow, Russia, May 7, 2019. The 74th anniversary of the victory over Nazi Germany in World War II will be marked here on May 9. (Xinhua/Bai Xueqi)

Russian servicemen march on the Red Square during a rehearsal for the Victory Day parade in Moscow, Russia, May 7, 2019. The 74th anniversary of the victory over Nazi Germany in World War II will be marked here on May 9. (Xinhua/Bai Xueqi)

Russian servicewomen march on the Red Square during a rehearsal for the Victory Day parade in Moscow, Russia, May 7, 2019. The 74th anniversary of the victory over Nazi Germany in World War II will be marked here on May 9. (Xinhua/Bai Xueqi)

Russian servicemen march on the Red Square during a rehearsal for the Victory Day parade in Moscow, Russia, May 7, 2019. The 74th anniversary of the victory over Nazi Germany in World War II will be marked here on May 9. (Xinhua/Bai Xueqi)

Russian military cadets march on the Red Square during a rehearsal for the Victory Day parade in Moscow, Russia, May 7, 2019. The 74th anniversary of the victory over Nazi Germany in World War II will be marked here on May 9. (Xinhua/Bai Xueqi)

Russian servicewomen march on the Red Square during a rehearsal for the Victory Day parade in Moscow, Russia, May 7, 2019. The 74th anniversary of the victory over Nazi Germany in World War II will be marked here on May 9. (Xinhua/Bai Xueqi)

Russian Defence Minister Sergei Shoigu (front) takes part in a rehearsal for the Victory Day parade in Moscow, Russia, May 7, 2019. The 74th anniversary of the victory over Nazi Germany in World War II will be marked here on May 9. (Xinhua/Bai Xueqi)

Russian military cadets march on the Red Square during a rehearsal for the Victory Day parade in Moscow, Russia, May 7, 2019. The 74th anniversary of the victory over Nazi Germany in World War II will be marked here on May 9. (Xinhua/Bai Xueqi)

Russian servicewomen march on the Red Square during a rehearsal for the Victory Day parade in Moscow, Russia, May 7, 2019. The 74th anniversary of the victory over Nazi Germany in World War II will be marked here on May 9. (Xinhua/Bai Xueqi)

Russian servicewomen march on the Red Square during a rehearsal for the Victory Day parade in Moscow, Russia, May 7, 2019. The 74th anniversary of the victory over Nazi Germany in World War II will be marked here on May 9. (Xinhua/Bai Xueqi)

Members of Russian honor guard take part in a rehearsal for the Victory Day parade in Moscow, Russia, May 7, 2019. The 74th anniversary of the victory over Nazi Germany in World War II will be marked here on May 9. (Xinhua/Bai Xueqi)

Russian Defence Minister Sergei Shoigu (C) takes part in a rehearsal for the Victory Day parade in Moscow, Russia, May 7, 2019. The 74th anniversary of the victory over Nazi Germany in World War II will be marked here on May 9. (Xinhua/Bai Xueqi)

Russian servicewomen march on the Red Square during a rehearsal for the Victory Day parade in Moscow, Russia, May 7, 2019. The 74th anniversary of the victory over Nazi Germany in World War II will be marked here on May 9. (Xinhua/Bai Xueqi)

Russian servicewomen march on the Red Square during a rehearsal for the Victory Day parade in Moscow, Russia, May 7, 2019. The 74th anniversary of the victory over Nazi Germany in World War II will be marked here on May 9. (Xinhua/Evgeny Sinitsyn)

Russian servicewomen salute during a rehearsal for the Victory Day parade in Moscow, Russia, May 7, 2019. The 74th anniversary of the victory over Nazi Germany in World War II will be marked here on May 9. (Xinhua/Evgeny Sinitsyn)

Soldiers march on the Red Square during a rehearsal for the Victory Day parade in Moscow, Russia, May 7, 2019. The 74th anniversary of the victory over Nazi Germany in World War II will be marked here on May 9. (Xinhua/Evgeny Sinitsyn)

Soldiers march on the Red Square during a rehearsal for the Victory Day parade in Moscow, Russia, May 7, 2019. The 74th anniversary of the victory over Nazi Germany in World War II will be marked here on May 9. (Xinhua/Evgeny Sinitsyn)

Soldiers attend the Victory Day parade rehearsal in Moscow, Russia, on May 7, 2019. The 74th anniversary of the victory over Nazi Germany in World War II will be marked here on May 9. (Xinhua/Evgeny Sinitsyn)

Soldiers march on the Red Square during a rehearsal for the Victory Day parade in Moscow, Russia, May 7, 2019. The 74th anniversary of the victory over Nazi Germany in World War II will be marked here on May 9. (Xinhua/Evgeny Sinitsyn)

Russian servicewomen march on the Red Square during a rehearsal for the Victory Day parade in Moscow, Russia, May 7, 2019. The 74th anniversary of the victory over Nazi Germany in World War II will be marked here on May 9. (Xinhua/Evgeny Sinitsyn)