Prime Minister Narendra Modi arrived in Russia on Monday, as the Indian leader treaded a fine line between maintaining a longstanding relationship with Moscow and courting closer Western security ties.

The visit is Modi's first since Russia launched its campaign in Ukraine and since he was returned to power last month as leader of the world's most populous country.

"I look forward to reviewing all aspects of bilateral cooperation with my friend President Vladimir Putin and sharing perspectives on various regional and global issues," said Modi in a statement. "We seek to play a supportive role for a peaceful and stable region."

Moscow remains a key supplier of cut-price oil and weapons to India, but the Kremlin's isolation from the West and blooming friendship with Beijing have impacted its time-honoured partnership with New Delhi.

Western powers have in recent years also cultivated ties with India as a bulwark against China and its growing influence in the Asia-Pacific, while pressuring it to distance itself from Russia.

Modi last visited Russia in 2019 and hosted Putin in New Delhi two years later, weeks before Russia began its offensive against Ukraine.

"Indian Prime Minister Modi arrived in Russia on an official visit," state media agencies confirmed on Monday afternoon.

India has shied away from explicit condemnation of Russia ever since and has abstained on United Nations resolutions censuring Moscow.

But Russia's fight with Ukraine has also had a human cost for India.

New Delhi said in February it was pushing the Kremlin to send back some of its citizens who had signed up for "support jobs" with the Russian military, following reports some were killed after being forced to fight in Ukraine.

Moscow's deepening ties with China have also been a cause for concern.

Washington and the European Union accuse China of selling components and equipment that have strengthened Russia's military industry -- allegations Beijing strenuously denies.

China and India are intense rivals competing for strategic influence across South Asia.

India is part of the Quad grouping with the US, Japan and Australia that positions itself against China's growing assertiveness in the Asia-Pacific region.

Oil and arms

New Delhi and the Kremlin have maintained a close relationship since the Cold War, and Russia was for a long time India's largest arms supplier.

But Ukraine has stretched Russia's arms supplies thin, forcing India to eye other sources for weapons -- including growing its own defence industry.

Russia's share of Indian imports of arms has shrunk considerably in recent years, according to the Stockholm International Peace Research Institute.

At the same time, India has become a major buyer of Russian oil, providing a much-needed export market for Moscow after it was cut off from traditional buyers in Europe.

That has dramatically reshaped energy ties, with India saving itself billions of dollars while bolstering Moscow's war coffers. India's month-on-month imports of Russian crude "increased by eight percent in May, to the highest levels since July 2023," according to commodity tracking data compiled by the Centre for Research on Energy and Clean Air.

But this has also resulted in India's trade deficit with Russia rising to a little over $57 billion in the past financial year.

From Russia, Modi will travel to Vienna for the first visit to the Austrian capital by an Indian leader since Indira Gandhi in 1983. (AFP)