Iranian negotiator Abbas Araqchi expressed doubt about clinching a nuclear deal with world powers Saturday, without saying whether talks would continue for a fifth day in Geneva, media reported. "Intense and difficult negotiations are under way and it is not clear whether we reach an agreement tonight," Fars news agency quoted Araqchi as saying. "The dispute is over the wording." The two sides are hoping to reach a long elusive deal under which Iran would freeze or curb parts of its controversial nuclear programme in exchange for some relief from crippling sanctions.