The UN's atomic agency has put off a decision on whether to report Iran to the UN Security Council over fears it is developing a nuclear weapon.
The emergency session of the International Atomic Energy Agency board of governors in Vienna will resume tomorrow.
An agency spokesman, announcing that today's planned session would not take place, did not give a reason for the delay.
Demands by some non-aligned countries to include mention of a Middle East nuclear-weapons-free zone in the IAEA resolution on Iran are understood to be complicating the talks.