Donald Trump has imposed an additional 25 per cent tariff on Indian imports as a punishment for the country importing Russian oil, which is a key revenue maker for Moscow's war in Ukraine.
The tariff is set to take effect in three weeks and would be added on top of a separate 25 per cent tariff entering into force on Thursday, taking India's tariff rate to 50 per cent.
It maintains exemptions for items targeted by separate sector-specific duties, such as steel and aluminium, and categories that could be hit like pharmaceuticals.
The White House said Mr Trump signed an executive order implementing the move on Wednesday, US time.
The order also threatens potential penalties on other countries deemed to be "directly or indirectly importing Russian Federation oil."
In a statement the Indian government said it was "extremely unfortunate that the US should choose to impose additional tariffs on India for actions that several other countries are also taking in their own national interest".
It said India's imports were based on market factors and aimed at energy security for its population of 1.4 billion.
Relations between Washington and New Delhi have deteriorated to new lows in recent weeks, with a trade agreement yet to be signed between the two countries.
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 because of the war.
The reshaping of energy ties has saved India billions of dollars while bolstering Moscow's coffers.
India argued it "began importing from Russia because traditional supplies were diverted to Europe after the outbreak of the conflict".
Mr Trump has threatened higher tariffs on Russia and secondary sanctions on its allies, if Russian President Vladimir Putin does not move to end the war in Ukraine.
India's national security adviser was in Moscow on Wednesday, media in New Delhi reported, coinciding with a visit by US envoy Steve Witkoff.
ABC/wires