MOSCOW -- Russia held its annual Victory Day parade on the Red Square on Saturday, marking the 81st anniversary of the victory in the Soviet Union's Great Patriotic War.

Addressing troops and guests ahead of the parade, Russian President Vladimir Putin said Victory Day is the country's "sacred, bright and most important" holiday.

He said preserving the memory of the events of the Great Patriotic War, as well as its true history and heroes, is a matter of honor for the country and the Russian people, adding that Soviet soldiers suffered great losses and made a great sacrifice in the name of freedom and dignity of the peoples of Europe.

Putin said Russian soldiers today are confronting an aggressive force armed and supported by the entire North Atlantic Treaty Organization (NATO) bloc, and they continue to move forward despite the situation.

The troop march included a contingent from the Democratic People's Republic of Korea.

The parade ended with an airshow over the square.

Following the parade, Putin and foreign leaders who had arrived in Moscow for the celebrations laid flowers at the Tomb of the Unknown Soldier at Alexander Garden.

Russia has held the Victory Day parade and a series of celebrations on May 9 annually since 1995.