Russian army soldiers march along Red Square during a general rehearsal for the Victory Day military parade which will take place at Moscow's Red Square on May 9 to celebrate 70 years after the victory in WWII, in Moscow, Russia, Thursday, May 7, 2015. (Photo by Alexander Zemlianichenko/AP Photo)

Serbian army soldiers march along the Red Square during a general rehearsal for the Victory Day military parade which will take place at Moscow's Red Square on May 9 to celebrate 70-years after the victory in WWII, in Moscow, Russia, Thursday, May 7, 2015. (Photo by Ivan Sekretarev/AP Photo)

Russian army soldiers march along Red Square during a general rehearsal for the Victory Day military parade which will take place at Moscow's Red Square on May 9 to celebrate 70 years after the victory in WWII, in Moscow, Russia, Thursday, May 7, 2015. (Photo by Alexander Zemlianichenko/AP Photo)

Russian army soldiers march along the Red Square during a general rehearsal for the Victory Day military parade which will take place at Moscow's Red Square on May 9 to celebrate 70 years after the victory in WWII, in Moscow, Russia, Thursday, May 7, 2015. (Photo by Alexander Zemlianichenko/AP Photo)

Russian army officers discuss a situation with a crew member of the new Russian T-14 Armata tank at the Red Square during a preparation for general rehearsal for the Victory Day military parade which will take place at Moscow's Red Square on May 9 to celebrate 70 years after the victory in WWII, in Moscow, Russia, Thursday, May 7, 2015. One of the tanks moving on Red Square suddenly stopped while others drove away. The engine was still rumbling but it wouldn't move. After an attempt to tow it away the T-14 rolled away about 15 minutes later. (Photo by Alexander Zemlianichenko/AP Photo)

A Russian T-14 Armata tank is ready to be towed in Red Square during a preparation for general rehearsal for the Victory Day military parade which will take place at Moscow's Red Square on May 9 to celebrate 70 years after the victory in WWII, in Moscow, Russia, Thursday, May 7, 2015. (Photo by Alexander Zemlianichenko/AP Photo)

Russian army officers speak a crew member of new a Russian T-14 Armata tank at the Red Square during a preparation for general rehearsal for the Victory Day military parade which will take place at Moscow's Red Square on May 9 to celebrate 70 years after the victory in WWII, in Moscow, Russia, Thursday, May 7, 2015. (Photo by Alexander Zemlianichenko/AP Photo)

Russian army self-propelled howitzers drive along at the Red Square during a general rehearsal for the Victory Day military parade which will take place at Moscow's Red Square on May 9 to celebrate 70 years after the victory in WWII, in Moscow, Russia, Thursday, May 7, 2015. (Photo by Alexander Zemlianichenko/AP Photo)

Chinese army soldiers march along the Red Square during a general rehearsal for the Victory Day military parade which will take place at Moscow's Red Square on May 9 to celebrate 70 years after the victory in WWII, in Moscow, Russia, Thursday, May 7, 2015. (Photo by Alexander Zemlianichenko/AP Photo)

Russian navy sailors take part in a rehearsal for the Victory Day parade in Red Square in central Moscow, Russia, May 7, 2015. Russia will celebrate the 70th anniversary of the victory over Nazi Germany in World War Two on May 9. (Photo by Sergei Karpukhin/Reuters)

Ka-52 “Alligator” military helicopters fly in formation above Red Square and the Kremlin during a rehearsal for the Victory Day parade in central Moscow, Russia, May 7, 2015. (Photo by Maxim Zmeyev/Reuters)

Russian servicemen drive Kurganets-25 infantry fighting vehicles during a rehearsal for the Victory Day parade in Red Square in central Moscow, Russia, May 7, 2015. (Photo by Sergei Karpukhin/Reuters)

Russian servicemen drive self-propelled howitzers Koalitsiya-SV during a rehearsal for the Victory Day parade in Red Square in central Moscow, Russia, May 7, 2015. (Photo by Sergei Karpukhin/Reuters)

Russian servicemen drive T-90 tanks during a rehearsal for the Victory Day parade in Red Square in central Moscow, Russia, May 7, 2015. (Photo by Sergei Karpukhin/Reuters)

Russian servicemen dressed in historical uniforms take part in a rehearsal for the Victory Day parade in Red Square in central Moscow, Russia, May 7, 2015. (Photo by Grigory Dukor/Reuters)

Russian servicemen dressed in historical uniforms take part in a rehearsal for the Victory Day parade in Red Square in central Moscow, Russia, May 7, 2015. (Photo by Grigory Dukor/Reuters)

Russian Cossacks take part in a rehearsal for the Victory Day parade in Red Square in central Moscow, Russia, May 7, 2015. (Photo by Grigory Dukor/Reuters)

Russian servicemen drive a T-14 Armata tank (front) during a rehearsal for the Victory Day parade in Red Square in central Moscow, Russia, May 7, 2015. (Photo by Sergei Karpukhin/Reuters)

Russian navy sailors march during a rehearsal for the Victory Day parade in Red Square in central Moscow, Russia, May 7, 2015. (Photo by Grigory Dukor/Reuters)

Su-25 “Frogfoot” Russian ground-attack planes fly in formation above Red Square, with a historical monument to Minin and Pozharsky seen in the foreground, during a rehearsal for the Victory Day parade in central Moscow, Russia, May 7, 2015. (Photo by Sergei Karpukhin/Reuters)

Russian servicemen march during a rehearsal for the Victory Day parade in Red Square in central Moscow, Russia, May 7, 2015. (Photo by Grigory Dukor/Reuters)

Russian servicemen march during a rehearsal for the Victory Day parade in Red Square in central Moscow, Russia, May 7, 2015. (Photo by Sergei Karpukhin/Reuters)

A T-14 Armata tank (L) comes to a stop during a rehearsal for the Victory Day parade in Red Square, with towing ropes attached to it, in central Moscow, Russia, May 7, 2015. (Photo by Grigory Dukor/Reuters)

Russian servicewomen march during a rehearsal for the Victory Day parade in Red Square in central Moscow, Russia, May 7, 2015. (Photo by Grigory Dukor/Reuters)

Russian servicemen drive armoured personnel carriers (APC) during a rehearsal for the Victory Day parade in Red Square in central Moscow, Russia, May 7, 2015. (Photo by Grigory Dukor/Reuters)

Russian servicemen operate Buk-M2 surface-to-air missile systems during a rehearsal for the Victory Day parade in Red Square in central Moscow, Russia, May 7, 2015. (Photo by Grigory Dukor/Reuters)

A Russian Yars RS-24 intercontinental ballistic missile system drives during a rehearsal for the Victory Day parade in Red Square in central Moscow, Russia, May 7, 2015. (Photo by Grigory Dukor/Reuters)

A Russian serviceman salutes as he rides a T-34 Soviet-made tank during a rehearsal for the Victory Day parade in Red Square in central Moscow, Russia, May 7, 2015. (Photo by Grigory Dukor/Reuters)

Russian servicemen operate MSTA-S self-propelled howitzers during a rehearsal for the Victory Day parade in Red Square in central Moscow, Russia, May 7, 2015. (Photo by Grigory Dukor/Reuters)

A Russian Bumerang (Boomerang) wheeled armored personnel carrier drives during a rehearsal for the Victory Day parade in Red Square in central Moscow, Russia, May 7, 2015. (Photo by Grigory Dukor/Reuters)

Russian servicemen drive T-90 tanks during a rehearsal for the Victory Day parade in Red Square in central Moscow, Russia, May 7, 2015. (Photo by Grigory Dukor/Reuters)

Russian servicemen drive T-14 “Armata” tanks during a rehearsal for the Victory Day parade in Red Square in central Moscow, Russia, May 7, 2015. (Photo by Grigory Dukor/Reuters)

Russian S-400 air defence mobile missile launching systems drive during a rehearsal for the Victory Day parade in Red Square in central Moscow, Russia, May 7, 2015. (Photo by Grigory Dukor/Reuters)

Russian air force jets fly in formation during a rehearsal for the Victory Day parade above central Moscow, Russia, May 7, 2015. (Photo by Grigory Dukor/Reuters)

A Russian Il-78 air force tanker and Su-24 jets fly during a rehearsal for the Victory Day parade in central Moscow, Russia, May 7, 2015. (Photo by Grigory Dukor/Reuters)

Russian Defence Minister Sergei Shoigu salutes during a rehearsal for the Victory Day parade in Red Square in central Moscow, Russia, May 7, 2015. (Photo by Grigory Dukor/Reuters)

A Russian serviceman holds a red flag onboard a T-14 Armata tank after it stopped during a rehearsal for the Victory Day parade in Red Square in central Moscow, Russia, May 7, 2015. A new high tech battle tank hailed by Russia as a “masterpiece” appeared to break down on Red Square on Thursday during a rehearsal for the military parade at which it will make its long-awaited debut. The tank's driver raised a small red flag to show he had problems but managed to drive on about 30 minutes later after an attempt to tow it away was abandoned, a Reuters witness said. (Photo by Grigory Dukor/Reuters)

Russian servicemen march during a rehearsal for the Victory Day parade in Red Square in central Moscow, Russia, May 7, 2015. (Photo by Grigory Dukor/Reuters)

Russian Defence Minister Sergei Shoigu salutes during a rehearsal for the Victory Day parade in Red Square in central Moscow, Russia, May 7, 2015. (Photo by Sergei Karpukhin/Reuters)

Russian army soldiers, dressed in WWII era uniforms, march along the Red Square during a general rehearsal for the Victory Day military parade which will take place at Moscow's Red Square on May 9 to celebrate 70 years after the victory in WWII, in Moscow, Russia, Thursday, May 7, 2015. (Photo by Alexander Zemlianichenko/AP Photo)

Indian army soldiers march along the Red Square during a general rehearsal for the Victory Day military parade which will take place at Moscow's Red Square on May 9 to celebrate 70 years after the victory in WWII, in Moscow, Russia, Thursday, May 7, 2015. (Photo by Ivan Sekretarev/AP Photo)

Russian army soldiers march along the Red Square during a general rehearsal for the Victory Day military parade which will take place at Moscow's Red Square on May 9 to celebrate 70 years after the victory in WWII, in Moscow, Russia, Thursday, May 7, 2015. (Photo by Ivan Sekretarev/AP Photo)

Russian military planes fly over, as Russian T-14 Armata tank is ready to be towed at the Red Square during a preparation for general rehearsal for the Victory Day military parade which will take place at Moscow's Red Square on May 9 to celebrate 70 years after the victory in WWII, in Moscow, Russia, Thursday, May 7, 2015. (Photo by Alexander Zemlianichenko/AP Photo)

Chinese army soldiers march along the Red Square during a general rehearsal for the Victory Day military parade which will take place at Moscow's Red Square on May 9 to celebrate 70 years after the victory in WWII, in Moscow, Russia, Thursday, May 7, 2015. (Photo by Ivan Sekretarev/AP Photo)

Russian army soldiers, dressed in WWII era uniforms, march along the Red Square during a general rehearsal for the Victory Day military parade which will take place at Moscow's Red Square on May 9 to celebrate 70 years after the victory in WWII, in Moscow, Russia, Thursday, May 7, 2015. (Photo by Ivan Sekretarev/AP Photo)

Indian army soldiers march along the Red Square during a general rehearsal for the Victory Day military parade which will take place at Moscow's Red Square on May 9 to celebrate 70 years after the victory in WWII, in Moscow, Russia, Thursday, May 7, 2015. (Photo by Ivan Sekretarev/AP Photo)

Russian army planes fly over Moscow during a general rehearsal for the Victory Day military parade which will take place at Moscow's Red Square on May 9 in in Moscow, Russia, Thursday, May 7, 2015. (Photo by Denis Tyrin/AP Photo)

A crew member of new Russian T-14 Armata drives his tank away from Red Square during a preparation for general rehearsal for the Victory Day military parade which will take place at Moscow's Red Square on May 9 to celebrate 70 years after the victory in WWII, in Moscow, Russia, Thursday, May 7, 2015. (Photo by Alexander Zemlianichenko/AP Photo)

Russian Su-25 assault aircrafts release smoke in the colours of the Russian flag while flying over Moscow's Red Square, on May 7, 2015, during a rehearsal for the Victory Day military parade. (Photo by Yuri Kadobnov/AFP Photo)

Russian soldiers take part in a rehearsal for the Victory Day military parade on May 7, 2015 on Red Square in Moscow. (Photo by Kirill Kudryavtsev/AFP Photo)