Two days of talks between the UN atomic agency and Iran have ended in Tehran, apparently without agreement, a diplomatic source told AFP on Thursday.
The International Atomic Energy Agency team was due to return to Vienna early Friday, the source said, following the talks aimed at clearing up concerns over Iran's nuclear programme.
A second source, a Western diplomat, told AFP that the latest he had heard on Thursday was that there were "still differences".
The head of the IAEA, Yukiya Amano, had last week also poured cold water on prospects for a deal, saying in Tokyo that he was "not necessarily optimistic".
The IAEA wants Iran to address what it believes is evidence of military efforts to develop a nuclear weapon carried out before 2003 and possibly since.
Chief inspector Herman Nackaerts returned from his last visit on December 14 saying he expected in January to conclude a long-elusive deal that would see Iran grant access to sites, scientists and documents related to these alleged activities.
Iran vehemently denies seeking or ever having wanted an atomic bomb and says that the IAEA's conclusions are based on forged documents -- material that it has not even been allowed to see.
Some observers suggested that Iran was waiting until after the IAEA talks to arrange a parallel meeting with six world powers -- the United States, China, Russia, Britain, France and Germany.
These talks are focused more on Iran's current activities, and in particular uranium enrichment. The last round ended in stalemate in June in Moscow./Trend/