The prime minister faces a choice between high tariffs or giving up cheap oil, putting New Delhi’s non-alignment policy under severe strain

The relationship between India and the US is facing one of its most significant challenges in decades, as the Trump administration doubles down on its demands that India stop buying Russian oil or face punitive tariffs.

The US president, Donald Trump, has refused to cut tariffs on Indian exports to the US, as he has for other countries, and on Monday said he would significantly raise them over its purchases of cheap Russian oil, which now account for one-third of its imported oil.