What is S-400 missile system that India will buy from Russia?
Russia has said it is preparing to supply S-400 Triumf anti-aircraft missile systems, one of the world's most advanced missile defence systems, to India. The system has the capability to destroy incoming hostile aircraft, missiles, and drones at ranges of up to 400 km. It can fire three types of missiles, create a layered defence, and simultaneously engage 36 targets.