Trump, who has previously denounced India as a “tariff king”, blamed New Delhi’s purchases of Russian weapons and oil for the additional rate, which puts at risk India’s largest export market, worth $87bn in the year to the end of March.

Narendra Modi has vowed to deepen India’s ties with Russia, despite Donald Trump’s tariff threats over buying Russian oil.

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.