A Treasury Department statement said Zarif was sanctioned because he “acted or purported to act for or on behalf of, directly or indirectly” Iran’s supreme leader, Ali Khamenei, who was sanctioned in late June. At that time, Mnuchin said measures would also be taken against Zarif, but they were delayed after State Department officials argued that would close the door to diplomacy....

An administration official said Trump remains ready to speak with Iranian leaders — just not Zarif.

Asked whether sanctioning Iran’s chief diplomat would limit U.S. ability to negotiate with Iran, if negotiations ever take place, a senior administration official said, “If we do have an official contact with Iran, we would want to have contact with someone who is a significant decision-maker.”....

When Zarif visited New York earlier this month on official U.N. business, Pompeo complained about all the interviews he granted to American journalists. Pompeo said that out of fairness, he should be allowed to address Iranian citizens directly on state television.