The skepticism went both ways.
"Definitely, a history of high tensions between Tehran and Washington will not go back to normal relations due to a phone call, meeting or negotiation," said Araghchi.
The U.S. and Iran broke ties after the 1979 Islamic Revolution when mobs stormed the U.S. Embassy in Tehran. A total of 52 hostages were held for 444 days.
Araghchi also reiterated Khamenei's statements that he is not optimistic about the potential outcome.
The focus now turns to negotiations among foreign ministers and other officials from the five permanent members of the U.N. Security Council plus Germany. The group wants Iran to present a more detailed proposal for a path forward before or at the next round of negotiations, scheduled in Geneva on Oct. 15-16.
If Iran complies, the oil-rich nation could see the easing of economic sanctions imposed after years of Iran's stonewalling inspections and secrecy about its nuclear activities. The West has long insisted on inspections, and Zarif now seems open to them.
"There may have been technical problems. They may have been problems of transparency, and we are prepared to address those problems," he said.
Zarif spoke Sunday on ABC's "This Week." Rice spoke to CNN's "Fareed Zakaria GPS." Kerry was interviewed on CBS' "60 Minutes."
Associated Press writer Nasser Karimi in Tehran, Iran, contributed to this report.
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