Chinese and Indian refiners are seeking alternative fuel supplies as they adapt to severe new U.S. sanctions on Russian producers and tankers that are designed to curb the revenues of the world's second-largest oil exporter.

U.S. and global benchmark crude-oil prices settled Monday at their highest since August as investors focused on the potential supply hit from further tightening of U.S. sanctions on Russia’s oil sector.

A fresh wave of U.S. sanctions against Russia’s oil industry threatened to disrupt global supplies, sending crude prices to their highest in more than four months.