John Kerry, Mohammad Javad ZarifIran and the U.S. have tentatively agreed on a formula that Washington hopes will reduce Tehran’s ability to make nuclear arms by committing it to ship to Russia much of the material needed for such weapons, diplomats say. In another sign of progress, the two diplomats told The Associated Press that negotiators at the December round of nuclear talks drew up for the first time a catalog outlining areas of potential accord and differing approaches to remaining disputes. The diplomats said differences still dominate ahead of the next round of Iran-six power talks on Jan. 15 in Geneva. But they suggested that even agreement to create a to-do list would have been difficult previously because of wide gaps between the sides. More