Referring to Prime Minister Narendra Modi as a as a "great friend", Russian President Vladimir Putin on Thursday extended a formal invitation to him for a separate bilateral meeting on the sidelines of the upcoming BRICS (Brazil-Russia-India-China-South Africa) summit in Russia's Kazan. Putn comments came today during his talks with National Security Advisor (NSA) Ajit Doval. The BRICS Summit is scheduled to be held in the Russian city of Kazan from October 22-24.