NEW DELHI: The government on Thursday approved the Rs 39,000-crore acquisition of five advanced Russian S-400 Triumf air defence missile systems, which have even rattled NATO countries because they can destroy incoming hostile aircraft, stealth fighters, missiles and drones at ranges of up to 400 km.The decision by the Manohar Parrikar-led defence acquisitions council ( DAC ), which will take some time to materialize into an actual deal after commercial negotiations, comes just ahead of PM Narendra Modi’s summit with Russian President Vladimir Putin in Moscow on December 24.TOI was the first to report on October 11 that the DAC was finalizing the game-changing S-400 acquisition — on a par with the soon-to-be-inked $5 billion deal for 36 French Rafale fighters in terms of sheer criticality — ahead of Modi’s visit to Russia.The DAC approval is just an “acceptance of necessity (AoN)” for Indian experts to now formally negotiate the government-to-government deal with their Russian counterparts. “It will take a few years for the S-400 systems to be actually inducted. The plan is to deploy three in the west (read Pakistan) and two in the east (read China) to seriously bolster the nation’s air defence capability,” said a source.With the IAF trying to steadily plug gaping holes in the country’s air defence coverage, including protection of strategic assets like nuclear reactors, the S-400 will come as a major shot in the arm for the force. India will be the second foreign customer for the S-400, which is designated ‘SA-21 Growler’ by NATO. China is slated to get deliveries of six S-400 batteries from 2017 onwards after a $3 billion deal inked with Russia last year.The DAC on Thursday also cleared other modernization proposals worth Rs 25,985 crore, including the Rs 14,600-crore acquisition of six more regiments of the indigenous Pinaka multiple-launch rocket systems. The army already has two regiments of the 40-km range Pinaka systems, while two more were approved earlier. But the S-400 was the clear takeaway to add “real defence substance” to Modi’s visit to Russia, which will also see the two countries ink the inter-governmental agreement for the over $1 billion project to manufacture 200 Russian Kamov Ka-226T light utility helicopters under the ‘Make in India’ policy.Then, as earlier reported by TOI, India is also on course to acquire a second nuclear-powered submarine on a $1.5 billion lease from Russia. Indian Navy had inducted the first Akula-II submarine, christened INS Chakra, on a 10-year lease from Russia in April 2012, under a secret $900 million deal inked way back in January 2004.When the S-400 contract is actually inked, it will among the largest-ever deals with Russia, which has been displaced by the US as India’s largest defence supplier over the last four years.The other big deals inked with Russia include the ones for 272 Sukhoi-30MKI fighters (over $12 billion) and INS Vikramaditya ($2.33 billion for the aircraft carrier and another $2 billion for 45 MiG-29Ks to operate from its deck).