- India signs deal with Russia despite threat of US sanctions
- In joint address PM Modi says Russia has always stood by India
- This is the third meeting between PM Modi and Mr Putin this year
Here are the 10 latest developments in this story:
"In this fast-changing world, our ties have grown at a fast pace. With time, the relations between our countries have gone from strength to strength," PM Modi said in a joint statement with Mr Putin.
New Delhi, which disregarded warnings of US sanctions to go ahead with the S-400 deal, kept the announcement low-key. "As and when the government approves it, delivery (of the missiles) will be in 24 months," Air Force chief BS Dhanoa has told reporters.
The S-400 is one of the world's most advanced long-range air defence systems. China was the first nation to buy the S-400 missile system in 2014. Russia has already started deliveries of an undisclosed number of the S-400 missile system to Beijing.
India hopes that US President Donald Trump's administration will give it a waiver on the weapons systems which New Delhi sees as a deterrent against China whose growing military muscle has spooked Washington too.
In its first reaction to the deal from the embassy in Delhi, the US said that the sanctions on Russia were intended to impose costs for its "malign behaviour" and not "impose damage to the military capabilities of our allies or partners". Saying that it cannot prejudge any sanctions decisions, the US said waivers, if any, will be considered on a transaction-by-transaction basis.
India and Russia also signed several agreements in space, nuclear energy and railways. The two leaders reportedly discussed key regional and global issues, including US sanctions on import of Iranian crude oil.
Besides a pact to help develop six nuclear power projects in India, Russia also agreed to train astronauts for India's first crewed space mission "Gaganyaan" in 2022.
"We have agreed to step up cooperation with India in combating the menace of terrorism and drug trafficking," said Mr Putin, who is being accompanied by a high-level delegation that includes Deputy Prime Minister Yuri Borisov, Foreign Minister Sergey Lavrov and Trade and Industry Minister Denis Manturov.
This is the third meeting between PM Modi and Mr Putin this year after the informal meeting in the Russian resort city of Sochi in May and a bilateral on the sidelines of the BRICS Summit in South Africa. Russia is one of only two countries with which India holds annual bilateral summits, the other being Japan.
Russia and India have been close since the 1950s and Moscow remains its biggest source of weaponry. But Indo-Russian annual trade has slipped below $10 billion since 2014, as PM Modi cultivated closer diplomatic and economic ties with Washington, while Russia has courted Pakistan and China.
(With inputs from AFP)