India is set to buy weapons from Russia worth more than $7 billion, the Kommersant newspaper reported Monday, citing unidentified sources in Delhi close to the government.

The deal on supplies of military equipment is due to be signed on Dec. 24-25, during the first visit of the Indian Prime Minister Narendra Modi to Moscow.

Military and technical cooperation will be a key issue during Modi's visit, Kommersant reported.

Last week, India's Defense Acquisition Council approved the purchase of Russia's S-400 air-defense missile systems.

India, which is planning to purchase at least five of the systems, according to several top-managers of Russian defense enterprises cited by Kommersant, will become Russia's second foreign buyer of S-400 after China.

The value of the deal is estimated at $2.5 billion, the newspaper reported.

In addition, Russia and India are expected to discuss the agreements on the purchase of two Varshavyanka-class diesel-electric submarines, 48 Mi-17V-5 military transport helicopters, 150 BMP-2/2K armored fighting vehicles and three Project 11356 frigates.

“We are also waiting for the decision on leasing the second nuclear Project 971 submarine,” an unidentified source in the military-technical cooperation sphere told the newspaper.

The total value of contracts is estimated at more than $7 billion, the newspaper reported.

India is Russia's biggest buyer of military hardware. In 2014, India purchased military hardware from Russia worth $4.7 billion, which accounted for 28 percent of Russia's total arms exports, according to Kommersant.