India’s state-owned oil refiners have not imported Russian crude over the past week as discounts have narrowed and U.S. President Donald Trump warned that buyers of Russian oil could soon face steep tariffs, Reuters reported Thursday, citing industry sources.

Indian Oil Corporation (IOC), the country’s largest refiner, was among those to halt purchases. IOC operates 10 of India’s 20 refineries, with a combined annual capacity of 60 million metric tons.

Other major state-owned refiners — Hindustan Petroleum, Bharat Petroleum and Mangalore Refinery and Petrochemicals — have also paused Russian oil imports, according to the same sources.

Executives at the affected companies told Reuters that Indian refineries are now turning to the spot market to fill supply gaps, ramping up purchases from Middle Eastern OPEC members and West African producers.