Royal Dutch Shell has halted its Arctic drilling after one day when sea ice encroached on its drilling ship in the Chukchi Sea.
Shell won a temporary permit to operate its drilling rig off Alaska just days ago. It has spent about $4.5bn (£2.8bn) on its Arctic efforts but its spill containment system has yet to be approved by the US Coast Guard.
The Chukchi Sea, north of the Bering Strait, is navigable for only a few months a year. Shell has asked the US government to extend its oil drilling season beyond the 24 September deadline.