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 Xinping for the Shanghai Co-operation Organisation summit, which is being seen as a challenge to US President Donald Trump and US dominance on a global level.

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, which are a key source of funds for 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 being seen in the context of the Trump threats.

For his part, Putin was facing a Trump-issued deadline to agree to hold peace talks with Ukraine's President Volodymyr Zelensky.

Speaking at the summit in Tianjin, Putin thanked the Chinese and Indian leaders for their support and their efforts to 'facilitate the resolution of the Ukrainian crisis'.