WASHINGTON—The U.S. expects all countries to cut oil imports from Iran to “zero” by Nov. 4 or risk sanctions, a senior U.S. State Department official said on Tuesday, expressing a toughening of the Trump administration’s Iran policy as Washington tries to politically and economically isolate Tehran.
Buyers of Iranian crude had expected the U.S. would allow them time to reduce their oil imports over a much longer period, by issuing sanctions waivers for nations that made significant efforts to cut their purchases. That expectation...