Medvedev, speaking during a parade in Red Square, said Russia must protect the peace achieved by the victory over Nazi Germany in World War II.
"The duty of our generation is to safeguard peace achieved by the victory," Medvedev said in an RIA Novosti report. He said modernization and the development of Russia's military are priorities for the government.
Prime Minister Vladimir Putin and Defense Minister Anatoly Serdyukov also attended the parade, in which about 20,000 members of the military marched in new-style field uniforms.
The military displayed more than 100 pieces of military hardware, including Topol-M ballistic missile launchers, T-90 battle tanks and BTR-80 armored personnel carriers.
The parade culminated with a flyover by five Mi-8 helicopters carrying Russian state and military flags.