Russia's Ministry of Defence (MoD) has deployed the fourth regiment of S-400 Triumf air defence missile systems on combat duty in the port city of Nakhodka in Primorye Territory, Eastern Russia.
An Eastern Military District spokesman told RIA Novosti that the official ceremony had taken place on 16 August 2012.
Russia's S-400 Battalions are now currently stationed in the Moscow region, the Baltic exclave of Kaliningrad and in the Eastern Military Distric respectively.
Developed by central design bureau Almaz as an upgrade to the S-300 missile system. The S-400 Triumph is a long to medium-range surface-to-air missile (SAM) system, designed to intercept a wide range of ground-based and airborne targets.
Airborne targets, such as stealth aircraft, unmanned aerial vehicles (UAVs), and cruise and ballistic missile threats are successfully destroyed by the system at a distance of up to 400km, at an altitude of 40,000m to 50,000m and a speed of up to three miles per second.
Code named SA-21 Growler, the S-400 system features three different missiles, including the extremely long-range 40N6, 48N6 long-range, as well as a 9M96 medium-range missile to destroy incoming targets.
The Russian MoD has no plans to export the S-400 systems, while the system will be used only by the Russian Armed Forces to replace S-300 systems.
A total of 56 battalions are expected to be armed with S-400 systems by 2020, to serve as a cornerstone of Moscow's theatre air and missile defences.