Triumf S-400
© Alexei Danichev / Sputnik Triumf S-400 air defense systems.
Russia and India have signed a contract for the supply of advanced S-400 air defense systems, Indian officials said, according to Russian news agencies. The delivery will happen "as soon as possible," he said. The signing of the contract has been confirmed by an Indian official at an international security forum in Moscow, RIA Novosti and Interfax news agencies reported. Russia's Defense Ministry has not yet commented on the reports. The S-400 is the latest and most advanced of the long-range surface-to-air missiles produced by Russia.

The Russian military is the only operator of the system, but China and India are expected to be the first foreign nations to receive it. Media reports in 2015 said that India wants to buy five S-400 battalions.