Russia has submitted a detailed proposal to India for supplying five additional S-400 “Sudarshan” long-range air defence squadrons, taking forward a procurement estimated to cost more than Rs 50,000 crore as the Indian Air Force seeks to substantially expand its long-range missile defence network.
Defence sources said Moscow’s response to the Indian tender has been received and is currently being processed by the Defence Ministry. The development follows the Defence Acquisition Council’s approval in March for additional S-400 systems as part of a wider package of defence procurements. The government’s official announcement at the time confirmed clearance for additional S-400 long-range surface-to-air missile systems, though it did not disclose the number or individual cost of the proposed purchase.
If the acquisition of five more squadrons is completed, India’s planned S-400 strength would rise to 10 squadrons, significantly widening the geographical coverage of the country’s long-range air defence network.
New deliveries could begin three years after deal
India signed its original contract with Russia in October 2018 for five S-400 squadrons in a deal valued at about $5.4 billion. Deliveries were subsequently affected by delays, partly amid disruptions linked to the Russia-Ukraine war.
Four of the five systems ordered under that agreement have now reached India, with the fourth arriving in June this year. Defence sources said the fifth and final squadron under the original contract is expected to be delivered by November.
Under the fresh proposal, deliveries of the additional systems are expected to begin roughly three years after the contract is signed. The terms, pricing and delivery schedule remain subject to negotiations, and the submission of the Russian proposal does not by itself amount to the signing of a procurement contract.
The new squadrons are expected to reinforce air defence coverage across both the western and eastern fronts, where India faces different combinations of aircraft, drones, cruise missiles and other long-range aerial threats.
Operation Sindoor shaped fresh requirement
India’s move to acquire more S-400 systems follows their operational deployment during Operation Sindoor in 2025. Indian Air Force officials have publicly credited the Russian-origin platform with playing a significant role in restricting Pakistan Air Force operations during the confrontation.
Western Air Command chief Air Marshal Jeetendra Mishra recently said an S-400 had destroyed a Pakistani surveillance aircraft at a range of 314 km, describing it as possibly the longest recorded surface-to-air missile engagement. He also said the system was used against Pakistani fighter aircraft, including Chinese-origin J-10s.
These accounts reflect assessments by Indian military officials. Pakistan has disputed several Indian claims concerning aircraft losses during the conflict, and an independently established public accounting of all aerial losses remains unavailable.
The S-400 is designed to detect, track and engage a range of aerial targets, including combat aircraft, airborne surveillance platforms, drones and certain categories of cruise and ballistic missiles. Its long engagement envelope also allows it to influence adversary aircraft operations without requiring them to cross into defended airspace.
India also expanding S-400 missile stockpile
Alongside the proposed purchase of additional systems, India is increasing the number of interceptors available for its existing S-400 fleet. More than 280 missiles are being procured to expand stocks and improve operational readiness, according to defence sources.
The expansion reflects a broader shift towards layered air and missile defence as drones, stand-off weapons and precision missiles assume a larger role in modern conflicts.
The S-400 forms only one layer of India’s air defence architecture. The country operates systems including the indigenous Akash family and Israeli-origin Barak systems, while command-and-control networks are intended to coordinate sensors and weapons with different engagement ranges.
The Defence Acquisition Council on March 27 granted Acceptance of Necessity for procurement proposals worth about Rs 2.38 lakh crore. The package included the S-400 for the Air Force along with medium transport aircraft, remotely piloted strike aircraft and overhaul of Su-30 aero-engine aggregates. An Acceptance of Necessity is an important step in India’s procurement process but does not constitute a final contract.
Project Kusha being developed as indigenous alternative
Even as India moves towards another large Russian acquisition, the Defence Research and Development Organisation is developing an indigenous long-range air defence system under Project Kusha.
The programme is intended to provide India with a domestically developed extended-range air defence capability and eventually complement the S-400 within a broader integrated network. Recent tests under the programme have demonstrated interception capabilities against simulated targets, though development is continuing.
India is simultaneously pursuing the broader Mission Sudarshan Chakra initiative aimed at creating a comprehensive national air defence shield by integrating detection, command-and-control and interception systems.
The proposed S-400 purchase also underscores the continuing importance of Russia in India’s defence inventory despite New Delhi’s efforts to diversify military procurement and increase indigenous manufacturing. India has expanded defence relationships with France, Israel and the United States while simultaneously retaining extensive Russian-origin platforms across its armed forces.
With Russia’s proposal now under evaluation, negotiations over price, delivery schedules, maintenance and other contractual provisions will determine when the proposed second S-400 order moves to the next stage.