Foreign ministry spokesman Randhir Jaiswal said this month that Modi had been invited to the May 9 parade, but had not confirmed if he would attend.

India's government said Wednesday that Russia had been informed that India would be represented by Singh.

Modi is focused on a response to arch-rival Pakistan, after a deadly attack targeting Indian tourists in Kashmir last week that New Delhi blames on Islamabad -- a claim that Islamabad rejects.

Modi visited Russia in October for a summit and President Vladimir Putin is expected to visit India later this year.

Russia has promised to hold its biggest World War II commemorations "in history" to mark 80 years since the Soviet Union and allied powers defeated Nazi Germany.