The top US Iran negotiator told a Senate panel Thursday that “the onus is on Iran” to bring a credible and verifiable action plan to the table at nuclear talks in Geneva next month for the US to determine if the new Iranian leadership is serious about a nuclear deal. Under Secretary of State for Political Affairs Wendy Sherman also urged Congress to hold off on new Iran sanctions until she and her counterparts hear from Iran’s Foreign Minister Mohammad Javad Zarif at the P5+1 talks in Geneva October 15-16th.

“We will know in the next short period of time whether there is anything serious here or not,” Sherman told the Senate Foreign Relations Committee Thursday.

“The onus is on Iran,” to bring a substantive plan to the Geneva talks, Sherman stressed. “We will not put ideas on the table until we hear from Iran.”

Iran’s Foreign Minister Zarif, in a meeting with Secretary of State John Kerry and other P5+1 foreign ministers in New York last week, said Iran would complete a comprehensive nuclear agreement within a year, Sherman told the committee. But a shorter term confidence building measure is desirable, Sherman said, to put time on the clock and reduce Iran's nuclear capabilities while that longer negotiation would take place.