President Donald Trump imposed an additional 25% tariff on India as punishment for importing Russian oil, according to a document posted on the White House website — an escalation of his trade battle with New Delhi and his first use of so-called secondary sanctions on countries the US says are fueling Moscow’s war machine.

India, which now faces among the highest tariff rates imposed by the US, called the levy "unjustified and unreasonable".

The Indian prime minister has said his country "is ready" to react to President Donald Trump's additional 25 percent levy on goods entering the U.S.