"Everyone knows that, at this point, it will be necessary to wait for the new Iranian government," Rafael Grossi said.
The IAEA does not take any direct part in the negotiations but has been called on to verify any nuclear steps agreed in the talks and to continue inspections in the country.
The source added that European powers Britain, France and Germany have decided to pause the submission of a resolution critical of Iran at the International Atomic Energy Agency in order to give diplomacy a chance and not harm the prospects of an informal nuclear meeting.
Director General Rafael Mariano Grossi will visit Tehran on Saturday for discussions with senior Iranian officials in order to find a mutually agreeable solution for the IAEA to continue essential verification activities in the country.