MOSCOW -- Russia may start shipping its S-400 air defence missile system to India in 2020, Dmitry Shugaev, director of the Russian Federal Service for Military-Technical Cooperation, said Monday.

"If we sign a contract with India by the end of the year, I think we can indeed expect deliveries in 2020," Shugaev was quoted by RIA Novosti news agency as saying.

Russian President Vladimir Putin reached an agreement on the supplies of S-400 at talks with Indian Prime Minister Narendra Modi in October 2016.

According to earlier reports, the value of the deal was estimated at around six billion U.S. dollars.

However, Shugayev said that Moscow is selling the system at a discount because India is considered Russia's strategic partner.

The official conclusion of the deal is expected to take place in October, ahead or at the 19th Russian-Indian summit.

Shugayev said that Russia and India had prepared everything necessary for signing the deal.

The S-400 air defense missile system is considered the most advanced of its kind in Russia, capable of destroying targets at a distance of up to 400 km and a height of up to 30 km.

Shugayev said that there is an opportunity to restart the joint Russian-Indian project of creating a fifth-generation fighter jet for the Indian Air Force, but did not provide details.

However, negotiations had reached a deadlock over the transition to a stage of full-fledged development of the aircraft, according to multiple media outlets.