India's Prime Minister, Narendra Modi, says he has had an 'insightful' exchange with Russian President Vladimir Putin on the sidelines of a summit in China.

The two leaders spent 45 minutes inside the Russian leader's car - after which Modi posted a picture of their journey alongside the compliment to Putin.

'They were at home... They felt comfortable there, and that's why they continued the conversation,' Putin's spokesman said.

The meeting came after scenes of hand-holding between the pair as they were hosted by China's Xi Jinping for the Shanghai Cooperation Organisation summit, which is seen as a challenge to US President Donald Trump's global dominance.

Trump has imposed US tariffs of 50% on goods from India as a way of punishing Delhi for buying Russian oil and weapons. The tariffs – among the highest in the world – include a 25% penalty for transactions with Russia, key to funding its war in Ukraine.

India, a vital strategic US partner in the Indo-Pacific, has shown no signs of stopping its purchases, and the camaraderie with Putin in Tianjin is contextualized by Trump's pressures.

Putin is currently facing a Trump-issued deadline for peace talks with Ukraine's President Volodymyr Zelensky, with no plans made announced for any such meeting.

Putin thanked the leaders of India and China for their support in efforts to resolve the Ukrainian crisis, as he described the discussions as optimistic.