modi putin
Russian President Vladimir Putin (L) shakes hands with India's Prime Minister Narendra Modi during a photo opportunity ahead of their meeting at Hyderabad House in New Delhi on 11 December 2014. PM Modi will visit Russia for a two-day summit on 23 December, 2015.Reuters

Indian Prime Minister Narendra Modi left for Russia on Wednesday to attend the annual summit between the two countries in Moscow, and key agreements on defence and nuclear energy are expected to be pushed through. 

The defence acquisitions that will be finalised at the 16th annual India-Russia summit are expected to reach  $10 billion. 

It will include the purchase of five S-400 Triumf air defence systems from Russia at an estimated cost of Rs. 40,000 crore after the Indian Defence Ministry cleared the purchase last week. The acquisitions will also see the purchase of Talwar class stealth frigates.

Russia is also looking to deliver Sukhoi T-50 (PAK FA) fighter jets to India for $3.7 billion, The Indian Express reported.

Nuclear energy will be among the topics up for discussion. 

"After Kudankulam, we are finalising a second site for Russian-designed reactors in India. We have outlined an ambitious vision for nuclear energy and construction of at least 12 reactors, which will have the highest safety standards in the world," PM Modi told Tass news agency. 

Some reports said that a site in Andhra Pradesh has been finalised for two nuclear reactors for the Kudankulam nuclear power plant.

Trade is also expected to be a focus at the summit. 

Currently, bilateral trade between Russia and India is a shade below $10 billion, and the two countries expect to raise it to $30 billion in the next decade, Foreign Secretary Subrahmanyam Jaishankar told the media on Tuesday. 

On the personal front, the two leaders have met on several occasions, with Russian President Vladimir Putin having visited India last December for the 15th summit.

Putin will host a private dinner for Modi on Wednesday night.