Killing a historic nuclear deal

Iran’s Foreign Minister Javad Zarif says a vote in US Congress for more sanctions against Iran will kill a likely nuclear deal with the West.
The warning comes amid official reports from the United States that certain lawmakers in Congress are drafting legislation to impose additional sanctions as Iran and the P5+1 group of countries are negotiating to reach a comprehensive agreement over Tehran’s nuclear energy program.
 In the words of FM Zarif: A sanctions bill by the US Congress will kill the joint plan of action that we adopted last year in Geneva. Now the president of the United States has the power to veto it, but our parliament will have its counteraction.
 Indeed, according to Iranian Parliament Speaker Ali Larijani, there are “retaliatory plans” in place in the event that the US Congress follows through on efforts to impose new sanctions. Larijani has promised a jump in expanding Iran’s nuclear technology to enrich uranium to the level of 60% for industrial use, saying the US will be responsible for the failure of the talks if this happens.
As things stand, it is evident that those who are busy drafting legislation to impose additional sanctions are not in favor of diplomacy or a likely deal. Numerous reports by the US intelligence services AND the International Atomic Energy Agency (IAEA) have verified to all IAEA members and NPT signatories "the non-diversion of the declared nuclear materials" by Tehran. Iran and the IAEA have likewise resolved all outstanding questions relevant to the implementation of the Safeguards Agreement.
 Into the argument, since the IAEA has verified the non-diversion of the nuclear materials, it has to stick to its guns and fulfill certain duties as well: