India’s plan to acquire five additional S-400 Triumf air defence systems from Russia has moved forward, with Moscow submitting a detailed proposal to New Delhi for cost negotiations. The proposal follows India’s decision earlier this year to expand its S-400 fleet after the system’s reported performance during Operation Sindoor in May 2025.Key HighlightsRussia has submitted its proposal for five additional S-400 squadrons.The proposed deal is estimated to be worth more than ₹50,000 crore.India’s Defence Ministry is currently examining the Russian proposal.The original 2018 S-400 contract was worth .43 billion for five systems.The final decision will require further negotiations and government approvals.The new systems are expected to strengthen India’s air defence on both western and eastern fronts.Russia Sends BOQ Proposal to IndiaMoscow has sent a Bill of Quantities (BOQ) proposal detailing the requirements and costs associated with the additional S-400 systems. The proposal has been received by India’s Defence Ministry and is currently under consideration.The estimated value of the new procurement is reported to be more than ₹50,000 crore, although the final cost will depend on negotiations between India and Russia.The proposal comes after the Defence Acquisition Council (DAC) cleared the procurement of five additional S-400 squadrons in March 2026. The acquisition is intended to further strengthen India’s layered air-defence network against aircraft, drones, cruise missiles and other aerial threats.India’s Existing S-400 DealIndia signed a .43 billion agreement with Russia in 2018 to acquire five S-400 systems. Deliveries began in 2021, and four of the five contracted systems have been received. The fifth and final system is expected to arrive by November 2026, according to defence sources.If the proposed procurement of five additional systems goes through, India’s planned S-400 inventory would rise to 10 squadrons.Why India Wants More S-400 SystemsThe S-400 has become a key component of India’s long-range air-defence architecture. The system is designed to detect and engage different types of aerial threats at varying ranges and altitudes.Its operational performance during Operation Sindoor in May 2025 further increased attention on the system. Indian defence officials have credited the S-400 with engaging high-value aerial targets during the military confrontation with Pakistan. Air Marshal Jeetendra Mishra has described an engagement at a range of around 314 km as possibly the longest recorded surface-to-air missile kill.India had already sought additional S-400 systems from Russia following Operation Sindoor, citing the need to strengthen its air-defence capabilities.New S-400 Deal May Include Indian ParticipationThe proposed procurement could involve greater Indian participation in maintenance and production. Reports indicate that discussions may include establishing a maintenance, repair and overhaul facility in India, along with possible technology-transfer arrangements.Under the reported proposal, some units could be procured directly from Russia, while others may involve domestic production. The additional systems would also complement India’s indigenous Project Kusha long-range air-defence programme.What Happens Next?The Russian proposal is now being evaluated by Indian authorities. Cost negotiations will be followed by the required government approvals before a final contract can be signed.The proposed acquisition comes as India continues to strengthen its air-defence network amid evolving security challenges along both its western and northern borders.Latest UpdateRussia has submitted its proposal for five additional S-400 Triumf squadrons, with the deal estimated at more than ₹50,000 crore. India is currently examining the proposal, and negotiations over the final cost and terms are expected to determine the next stage of the procurement process.
