Iran appointed career diplomat Reza Najafi as its new ambassador to the International Atomic Energy Agency (IAEA) on Tuesday, the official IRNA news agency reported. Najafi, a disarmament expert, previously headed the political and international affairs bureau at the foreign ministry after chairing the disarmament and international department there. He will replace Ali Asghar Soltanieh, who announced his resignation on Thursday after serving more than a decade in Vienna, where the IAEA is based. This comes as moderate President Hassan Rowhani continues to reshuffle his nuclear team, beginning with the appointment of ex-foreign minister Ali Akbar Salehi to head the country\'s Atomic Energy Organisation. Iran is at loggerheads with the IAEA over its nuclear activities, with the country\'s programme being monitored by inspectors. The IAEA says there is \"overall, credible\" evidence that until 2003 Iran conducted activities to develop nuclear weapons, despite Tehran\'s denials. It has engaged in many talks with Iranian officials in the past two years but has failed to convince them to grant it access to sites, documents and scientists involved in these alleged efforts. In parallel efforts, six world powers -- the US, China, Russia, France, Britain and Germany -- have tried to force Iran to cut back on its nuclear drive. They suspect Tehran is seeking to develop nuclear weapons, something it strongly denies. Their talks with Tehran, on hold over Iran\'s presidential election, have failed to yield any breakthrough. Rowhani has promised to re-engage the world powers and increase transparency on Iran\'s nuclear drive.