Russian Defense Minister Sergei Shoigu (Standing in the car) inspects troops during the Victory Day parade in Moscow, Russia, May 9, 2017. Russia marks on Tuesday the 72nd anniversary of the victory over Nazi Germany in World War II. (Xinhua/Bai Xueqi)

MOSCOW, May 24 (Xinhua) -- Russia will continue to build up its armed forces to counter challenges and defend its national interests, Russian Defense Minister Sergei Shoigu said Wednesday.

"The United States and other Western countries continue to impose the idea of Russian military threat on the international community, and many countries follow this policy," Shoigu told the upper house of the Russian parliament.

Against such a backdrop, Shoigu said the Russian Defense Ministry pays special attention to sustaining nuclear deterrence by upgrading nuclear triad -- land-based intercontinental ballistic missiles, strategic bombers and nuclear submarines.

He said the Russian Strategic Missile Forces has been receiving modern Yars International Ballistic Missiles, which have increased Russia's capability to penetrate missile shields. A total of 17 regiments will be re-armed with the Yars missiles by 2021.

According to Shoigu, Russia plans to modernize four to five strategic bombers every year. In 2016, the Russian Aerospace Forces received two upgraded Tu-160 and two Tu-95MS bombers.

After 2021, Russia plans to start mass production of the upgraded Tu-160M2 aircraft that can strike targets remotely without entering potential enemy's air defense zones.

Russia currently has nine modern strategic missile submarines and it aims to increase the number to 13, including seven "Borey"-class submarines equipped with "Bulava" missiles, Shoigu said.

Russia's state-of-the-art T-50 jets and anti-aircraft missile system S-500 will be delivered in 2019 and 2020 respectively, said Shoigu.