“This bill undercuts U.S. negotiating leverage by casting as an open question whether the U.S. can honor it commitments,” Jamal Abdi, of the National Iranian American Council, said in statement. “The uncertainty the bill creates regarding U.S. ability to provide sanctions relief, combined with the backlash that it could generate in Iran to limit their negotiators’ maneuverability, could very well mean greater U.S. concessions will be necessary to secure a deal.”