FILE - In this Oct. 28, 2013 file photo Iran's deputy Foreign Minister Abbas Araghchi, right, shakes hands with Director General of the International Atomic Energy Agency, IAEA, Yukiya Amano prior to a meeting at the International Center in Vienna, Austria. Nearly seven weeks after signing a landmark nuclear deal, representatives of Iran and six world powers hope to reach agreement this week on its implementation. But differences over Tehranís push to improve its uranium enrichment abilities could further delay enactment and strengthen critics of the accord in Washington and Tehran. A meeting, scheduled to start Thursday afternoon, Jan. 9, 2014 in Geneva, is formally being held by Araghchi and EU senior negotiator Helga Schmid, on behalf of the six world powers. (AP Photo/Hans Punz, File)