What is S-400 that India wants to buy from Russia? How it will make India stronger

New Delhi, News24 Bureau, Oct 5: Prime Minister Narendra Modi welcomed Russian President Vladimir Putin on his arrival here on Thursday. Putin is on a two-day visit during which India and Russia are likely to sign a deal to procure S-400 air defence systems. The leaders will also deliberate on key regional and global issues, including US sanctions on the import of Iranian crude oil. The Summit is being closely watched by both the US and China.S-400 is known as Russia's most advanced long-range surface-to-air missile defence system. China was the first foreign buyer to seal a government-to-government deal with Russia in 2014 to procure the lethal missile system and Moscow has already started delivery of an undisclosed number of the S-400 missile systems to Beijing.The S-400 is an upgraded version of the S-300 systems. The missile system, manufactured by Almaz-Antey, has been in service in Russia since 2007.Russia has been one of India's key suppliers of arms and ammunition.Sources had earlier said Modi and Putin would also deliberate on the impact of US sanctions on the import of crude oil from Iran.Besides holding talks with Modi, the Russian leader will also have a meeting with President Ram Nath Kovind as well as other official engagements, according to the Ministry of External Affairs.The last annual summit was held on June 1, 2017, during the visit of the prime minister to Russia.India wants to procure the long-range missile systems to tighten its air defence mechanism, particularly along the nearly 4,000-km-long Sino-India border

See this video to know why America is upset with this India-Russia Summit: