The U.S. believes that global oil supplies will exceed demand next year making it easier for countries to cut Iranian oil imports to zero, a senior U.S. official said on Friday as Washington prepares to reimpose sanctions on Iran. Brian Hook, the U.S. special representative for Iran, told reporters that Saudi Arabia had been “very helpful” in bolstering oil supplies while the U.S. moved to reimpose sanctions against Tehran. He said Saudi Arabia had “successfully insulated oil” from broader political issues linked to the killing of journalist Jamal Khashoggi.