Iran and major powers will continue negotiations on an historic nuclear deal past Tuesday ' s deadline for a long - term agreement, European Union foreign policy chief Federica Mogherini said. "We are continuing to negotiate for the next couple of days. This does not mean we are extending our deadline," Mogherini told Reuters’ reporters. The deal under discussion between Iran, Britain, China, France, Germany, Russia and the United States is aimed at curbing Tehran's most sensitive nuclear work for a decade or more, in exchange for relief from sanctions that have slashed Iran's oil exports and crippled its economy.