Oil futures ended sharply higher on Friday, as fresh U.S. sanctions on Russia’s oil sector looked to threaten global supplies and as winter storms in the U.S. were expected to boost demand for heating fuels.

The U.S. Treasury Department is sanctioning Russian oil companies, tankers, officials and executives. Oil prices jumped on worries that crude supplies would face disruptions. Oil prices jumped on Friday as the U.

Crude prices are having one of their best days in a year, rallying as much as 5% amid concerns that icy weather in the oil patch will crimp domestic supply, while tighter sanctions on Russia and Iran may eliminate barrels from global markets.