The envoys said a provisional agreement may be reached even earlier — by late Sunday. But they cautioned that final details of the pact were still being worked out and a formal agreement must still be reviewed by leaders in the capitals of Iran and the six world powers at the talks.
Senior U.S. and Iranian officials suggested, however, there was not enough time to reach a provisional deal by the end of Sunday.
All of the officials, who are at the talks, demanded anonymity because they weren't authorized to discuss the negotiations publicly.