India to buy 5 missiles priced at one billion dollars each. (File )
Prime Minister Narendra Modi will sign a deal this weekend with Russian President Vladimir Putin to acquire Moscow's most advanced air defence system.
India will sign up to acquire five S-400 'Triumph' anti-missile defence systems for 5 billion dollars, said sources.
Mr Putin will meet PM Modi in of Goa on Saturday on the sidelines of the BRICS Summit involving the leaders of Brazil, Russia, India, China and South Africa.
The S-400 is Russia's most modern air defence system and has been deployed to Syria, where Moscow is conducting a bombing campaign in support of long-time ally Syrian President Bashar al-Assad.
The system can track some 300 targets and shoot down around three dozen simultaneously over a range of several hundred kilometres.
An agreement with Russia to build frigates for the Indian Navy would also be signed on Saturday, as well as a deal to set up a joint venture in India to build multi-task Kamov-226 helicopters.
The defence deal will also include joint venture in India to build multi-task Kamov-226 helicopters.
India has signed a series of key defence deals under PM Modi as part of a $100 billion upgrade of its Soviet-era military hardware.
In September, after nearly a decade of discussions and setbacks, India signed a deal to acquire 36 French Rafale fighter jets for 7.9 billion euros ($8.8 billion) to bolster its military against an increasingly assertive China.