Four S-400 Triumf battalion sets to bolster air defense system in north-western Russia - Defense Ministry

MOSCOW. Jan 13 (Interfax) - Four battalion sets of S-400 Triumf air defense missile systems will be provided to the Air Force and Air Defense unit in Russia's Western Military District in 2017, the Russian Defense Ministry said.

"These S-400s will join the air defense system in the north-west of Russia," the Western Military District said in a press release, seen by Interfax-AVN on Friday.

Four air defense missile regiments equipped with advanced S-400 missile systems are currently on combat duty in the Leningrad and Moscow regions, it said.