US President Donald Trump says India has offered to cut its tariffs to nothing even as he called the current trade stalemate with the country a totally one sided disaster.

US tariffs of 50% on goods from India - which includes a 25% penalty for Delhi's refusal to stop buying oil from Russia - took effect last week.

India has not responded to Trump's latest comment but this war of words over Russian oil has caused Delhi-Washington ties to hit an all-time low.

Trump's comment coincides with Indian Prime Minister Narendra Modi attending the Shanghai Co-operation Organisation (SCO) summit in Tianjin where he met Chinese President Xi Jinping and Russian President Vladimir Putin.

Washington says Delhi has been indirectly funding Russia's war in Ukraine.

India buys most of its oil and military products from Russia, very little from the US, Trump wrote, adding Delhi should have cut tariffs years ago.

Delhi has previously said that oil supply from Russia was vital to meet the energy needs of its vast population.

It has also called the tariffs unfair, unjustified and unreasonable.

Last week, the country's commerce minister, Piyush Goyal, stated that India will neither bow down nor ever appear weak in its economic relationships with other countries.

Goyal also mentioned that the country was prepared to have a free-trade agreement with anyone who wanted it.

On Monday, Trump wrote: What few people understand is that we do very little business with India, but they do a tremendous amount of business with us. He emphasized that India sells massive amounts of goods to the US but purchases very little in return.

Until recently, the US was India's largest trading partner, and these tariffs have sparked fears that exports and growth in the world's fifth-largest economy could suffer.

At the SCO summit, Modi was seen shaking hands with Putin ahead of a meeting hosted by Xi, indicating India's growing ties with these leaders amid strained relations with the US.

Putin and Modi later spent 45 minutes together, a meeting which Modi described as having had an insightful exchange.