India has taken the next step towards buying 5 more S-400 Triumph air defence systems from Russia, with Moscow sending a cost proposal for the proposed acquisition. The document details construction and material expenses linked to deploying the systems, clearing the way for negotiations over the final price.
The purchase is not yet final. Price discussions will be followed by approval from the Ministry of Finance, after which the Cabinet Committee on Security will take the final decision.
What Russia’s proposal contains
The proposal is described as a Bill of Quantities, or BOQ. It includes the cost of construction and materials needed for deployment. Once the 2 sides negotiate the price, the proposal will move through the required approval process.
India and Russia signed an agreement in 2018 for 5 S-400 systems at a cost of about $5.43 billion. 4 units have been delivered, while the fifth and final system is expected to reach India in November. The article also says the last unit could arrive in November or December.
The new proposal concerns 5 additional squadrons. A squadron is a group of military aircraft or air-defence assets operated as a unit.
Why the system is central to the plan
The proposed expansion comes after the reported performance of the S-400 during Operation Sindoor in May 2025. The system was described as having an important role in India’s air-defence network during the operation.
According to the report, one of its long-range missiles struck a Pakistani airborne early warning and control aircraft at a distance of about 314 kilometres inside Pakistan. Pakistan also reportedly attempted to target Indian airbases where the S-400 was deployed with kamikaze drones. India’s air-defence network prevented Pakistani fighter aircraft from approaching close to the Indian border, the report said.
The S-400 is also described as capable of neutralising hypersonic threats. China has developed hypersonic missiles and a fleet of fifth-generation stealth fighter aircraft, while Pakistan obtains most of its weapons from China. These developments are presented as reasons for India to strengthen its air-defence capability for a potential 2-front conflict involving China and Pakistan.
Wider India-Russia defence discussions
The report says Russia has also offered India Su-57 fifth-generation fighter aircraft. India has shown interest in the proposal, but no decision has been taken to purchase 2 Su-57 squadrons.
China’s deployment of J-20 fifth-generation fighter aircraft in Tibet is identified as a major concern for India. The report also says discussions between New Delhi and Moscow could gain momentum around defence cooperation, hypersonic missile technology and other strategic weapon systems.
Russian President Vladimir Putin is expected to visit India during the proposed BRICS summit in Delhi from 11 to 13 September. The report links the possible visit to further discussions on defence cooperation, but it does not state that a new defence agreement has been finalised.
What happens next
The immediate step is negotiation over the cost of the 5 additional S-400 units. The proposal must then receive financial approval before the Cabinet Committee on Security considers the purchase.
The fifth system from the 2018 agreement is expected in November, with another reference placing its possible arrival in November or December. The final cost and approval status of the proposed additional units remain to be decided.
Conclusion
India’s plan to buy 5 more S-400 systems has moved into the pricing and approval stage after Russia sent a cost proposal. The purchase will depend on negotiations, Ministry of Finance approval and a final decision by the Cabinet Committee on Security.
Frequently Asked Questions
Q. What is India planning to buy from Russia?
India is considering the purchase of 5 additional S-400 Triumph air defence system units.
Q. What has Russia sent to India?
Russia has sent a Bill of Quantities proposal detailing construction and material costs linked to deploying the systems.
Q. Has India finally approved the additional S-400 purchase?
No. Price negotiations, Ministry of Finance approval and a decision by the Cabinet Committee on Security are still required.
Q. How many S-400 systems were covered by the 2018 agreement?
The 2018 agreement covered 5 S-400 systems for about $5.43 billion.
Q. When is the final system from the earlier agreement expected?
The fifth and final system is expected in November. The report also says it could arrive in November or December.
Q. What role did the S-400 reportedly play during Operation Sindoor?
The system was described as having an important role in India’s air-defence network during Operation Sindoor in May 2025.
Q. Has India decided to buy Su-57 fighter aircraft?
No. India has shown interest in Russia’s proposal, but no decision has been taken to buy 2 Su-57 squadrons.
