VIENNA, Austria (CNN) - A scheduled meeting between delegations from Iran, France, Russia and the International Atomic Energy Agency was delayed for several hours Tuesday, but the reason was unclear.
Iranian officials were scheduled to huddle with the other delegations at the IAEA headquarters in Vienna, but that meeting had not started eight hours after it was to have begun. It was not clear when or whether the meeting would take place.
The delegations were to scheduled to meet for a second day Tuesday to try to strike a deal about the future of Tehran's nuclear program.
Monday, talks among the representatives ended on an optimistic note, with the director-general of the U.N.'s nuclear watchdog agency calling them constructive.