The head of the UN nuclear watchdog is to visit Tehran this week as a December deadline looms for completion of a long-running investigation into its past activities, Iran's nuclear chief said, according to AFP.

A 12-strong team from the International Atomic Energy Agency was already headed to Iran and would be followed by director Yukiya Amano "in three or four days," Ali Akbar Salehi told Iranian television from Vienna late Monday. An IAEA spokesman confirmed that a visit by Amano was under consideration but said details were still being worked out.