Russia's Medvedev due in India to sign trade deals
Russian President Dmitry Medvedev arrives in India on Tuesday for a two-day official visit.
He is the latest in a series of foreign leaders to travel to Delhi to push for business deals and closer ties.
Nuclear and defence contracts worth billions of dollars are expected to be signed between the countries.
They have been allies since the Cold War but observers say Mr Medvedev will be keen to ensure that Russian firms do not lose out to foreign competitors.
In the past six months, India's Prime Minister Manmohan Singh has already welcomed the leaders of China, France, the US and the UK to Delhi.
Each has been accompanied by a large business delegation, and each has gone home boasting of billions of dollars of extra trade with one of the world's fastest growing economies, the BBC's Mark Dummett in Delhi reports.
Two areas in particular have attracted interest - India's ambitions to greatly expand and modernise its air force, and its plans to build a series of nuclear power generators.
It needs foreign technology and know-how for both, and the sums involved are massive, our correspondent says.
Reports say high on the agenda for President Medvedev's trip will be a $30bn agreement to design and develop a stealth fighter jet for the Indian air force.