Indian Prime Minister Narendra Modi is heading to Moscow for an annual bilateral summit expected to focus on defense and energy cooperation.
Modi was to arrive on the evening of December 23, in time for a private dinner with President Vladimir Putin.
The two leaders will hold their summit on December 24, before meeting with Indian and Russian business leaders.
The visit will also include a visit at the Emergency Situations Ministry and a speech at a "Friends of India" event.
Russia and India, whose leaders have held annual summits since 2000, have shared close ties since the Cold War and are now partners in the BRICS group of emerging-market countries.
"The best thing is that he knows how to maintain relations," Modi said of Putin in an interview with Russian state news agency TASS published on December 23. He said the countries had a "robust partnership in the field of defense, nuclear energy, science and technology, and other areas."
Modi and Putin will discuss defense and nuclear cooperation, as well as ways to work together in oil and coal, Indian Foreign Secretary S. Jaishankar told reporters on December 23.
According to Konstantin Makiyenko of the Center for Analysis of Strategies and Technologies, which advises Russia's Defense Ministry, some $7 billion worth of deals are expected to be agreed during Modi's visit.
India has been the world's biggest arms importer in the last five years.
But Russia has slipped behind the United States and Israel in securing orders in the Indian defense market, which is estimated to be worth $130 billion over the next seven years.
The Indian defense market could be a welcome diversion for Russia, as slumping oil prices and Western sanctions imposed over Russia's actions in Ukraine threaten the Russian government's efforts to pull the economy out of recession.
During Modi's trip, the two sides are expected to clarify an agreement to manufacture 200 Kamov-226T light military cargo helicopters in a joint venture. The deal is estimated at $1 billion.
Reports said other potential deals from the trip include the lease of a second nuclear-powered attack submarine from Russia, an Indian Navy order for three Russian frigates, and agreement to restart the joint development of an advanced "fifth-generation" fighter jet.
Talks are also likely to touch upon the purchase of five advanced S-400 air-defense missile systems by India, which the country's defense-acquisition panel approved last week.
The potential agreement, estimated to be worth some $4.5 billion, would be the country's biggest weapons deal with Russia since 2001, when India agreed to buy 140 Sukhoi 30MK fighter jets.
"Beyond speed, [the S-400 system] will also increase the ability of the Indian forces to engage multiple targets and at a long range," Anurag Garg of the PwC's strategy consulting group said. "This is important to restore the strategic balance of power with China in the region and to have a credible defense against Pakistan's fighters and ballistic missiles."
On the energy front, Indian Minister of State Jitendra Singh told lawmakers earlier this month that Modi's visit was expected to produce "bilateral decisions to expand cooperation in the nuclear power industry."
Indian and Russian sources were quoted as saying Modi will offer Russia a site in the southeastern state of Andhra Pradesh to build six nuclear reactors.
But a spokesman for Russian state nuclear company Rosatom, Sergei Novikov, said there were no plans yet to sign any contracts during the visit.
Russia is already building the Kudankulam nuclear power plant in Tamil Nadu, a state adjacent to Andhra Pradesh. The first unit was included in India's national energy grid in 2013 and work is under way at the second one.
In December 2014, the sides signed documents allowing the construction of a third and fourth units to begin.
Moscow and New Delhi signed a document outlining plans for the construction of more than 20 nuclear power units in India, joint uranium extraction and production of nuclear fuel, and nuclear waste disposal.
India is also turning to Russia to secure overseas energy assets.
The state-owned Indian Oil Corp and Oil India, whose chairmen are to accompany Modi in Moscow, are reportedly in talks with Russia's Rosneft to buy a stake in a Siberian oil project.
On the way home, Modi may stop by Kabul to inaugurate Afghanistan's new parliament built by India, Indian media reported.