United Nations nuclear chief Yukiya Amano has reached Iran to "clarify past and current issues" of the country's nuclear program, according to reports.
According to ABC News, Amano and his team were seen arriving at the Tehran airport on television footage.
It is the UN nuclear chief's second visit to Iran in three months.
Iran and the world powers have agreed to a landmark deal that that curbs the country's nuclear programme in return for the lifting of international economic sanctions.
