Modi was speaking after talks with President Vladimir Putin aimed at revitalising ties that have focused on the import of defence equipment. Even in that area, India has increasingly turned to countries such as the United States and Israel for its military modernisation programme.
"Even if India's options have increased, Russia remains our most important defence partner," Modi told reporters. He said Russia had also offered to manufacture an advanced helicopter in India.
Modi said that "we have met twice at the opposite ends of the world - at Brazil and Australia".
He recalled that President Putin and then prime minister Atal Bihari Vajpayee launched the annual summit process in 2000.
The prime minister said the two countries have "a strategic partnership that is incomparable in content". He added that Russia has been "a steadfast supporter" even in difficult moments of history.
Russia is most important defence partner and "we have conducted joint military drill of the three wings in the last six months", said Modi .