The U.N. nuclear watchdog and Iran ended a day of talks in Tehran on Wednesday, but there was no immediate word on the outcome, the Iran Students' News Agency reported.
The "negotiations between Iran and the Agency which started Wednesday morning ... ended a few minutes ago. There is still no news of the details from this meeting," ISNA said.
The International Atomic Energy Agency (IAEA) had hoped to bridge persistent differences with Iran preventing the Vienna-based U.N. agency from restarting a stalled investigation into suspected nuclear bomb research by Tehran, Reuters reported.
Iran denies Western allegations that it is seeking to develop the capability to make nuclear weapons.
Western diplomats accredited to the IAEA said they did not expect any breakthrough in Wednesday's talks in Tehran.
"Given Iran's uncompromising attitude and unwillingness to reach an agreement with the IAEA, I do not expect progress to be made," a Western envoy said.