A senior U.S. official in Vienna says Iran must significantly reduce its uranium-enrichment capacity if it wants to reach a lasting deal over its nuclear program.
The official, who spoke on condition of anonymity, was talking to reporters on July 3 as Iran and six world powers began a new round of negotiations in the Austrian capital aimed at securing a comprehensive nuclear deal by July 20.
The official said Tehran's enrichment capacity should be a "a fraction" of what it is now, adding that negotiators remained committed to the July 20 deadline despite "significant gaps" between the two sides.
The United States, Russia, China, France, Britain, and Germany want Iran to reduce its nuclear program to ease fears it might develop atomic weapons.
Iran says its nuclear activities are peaceful.