Tightened U.S. sanctions on Moscow have disrupted a roaring trade in discounted Russian oil to China and India, reviving demand for Middle Eastern and African crudes, roiling shipping markets and driving up oil prices.

Widened sanctions on Moscow by western countries including the United States have roiled global oil trade and forced buyers of discounted Russian crude to find new ways to maintain their purchases. "It is the responsibility of the supplier to deliver to me something that meets my requirements of compliance,

The amount of Russian and Iranian oil held on ships has hit multi-month highs as harsher U.S. sanctions reduced the number of buyers, leaving fewer tankers available to deliver cargoes and driving up crude costs,