A 50% tariff rate will be the highest levy among any U.S. trading partner, with some sectors of Indian economy more exposed than others.

President Donald Trump's economic policies are facing scrutiny as weak indicators emerge. Job gains are dwindling, inflation is rising and growth has slowed compared to last year.

"The key channel by which secondary tariffs on buyers of Russian energy could impact the global economy would be through the level of energy prices," says Kieran Tompkins from the consultancy Capital Economics. If the tariffs work, they will cut the flow of Russian oil and gas to global markets.