Russian President Vladimir Putin is on a two-day visit to India to hold the 19th India-Russia Annual Bilateral Summit with Prime Minister Narendra Modi. While the S-400 Truimf air missile defense system remains the main focus of the meet, a number of crucial agreements between the countries on economy, nuclear energy and space are expected to be signed by Putin and Modi. In the event of the signing of the missile deal, Russia would supply India the much-talked about S-400 Triumf, which is a Russian anti-air system which can shoot down ballistic missiles at a range of 60km (37 miles).