Russia will begin delivering surface-to-air missile systems to India by the end of 2021, state news agency RIA Novosti quoted a Russian official as saying on February 5.
India signed a $5-billion deal for S-400 missiles in 2018, prompting warnings from Washington that such an acquisition would trigger sanctions.
"The contract is being implemented on schedule. The first shipment is due by the end of 2021," deputy director of the Federal Service for Military-Technical Cooperation (FSMTC), Vladimir Drozhzhov, said at Defense Expo 2020 in Lucknow, India, RIA reported.
"The training of Indian specialists is to begin before this delivery," Drozhzhov was quoted as saying.
In November, the same agency cited the general director of Russian state arms exporter Rosoboronexport, Aleksander Mikheev, as saying deliveries would start in September 2021.
The United States was furious last year at NATO ally Turkey purchasing the Russian system, which Washington says is not compatible with NATO equipment.
Russia says the S-400 is capable of engaging airborne targets within a range of about 400 kilometers. A next-generation S-500 system, to extend that range to about 500 kilometers, is reportedly being developed.