Iran nuclear deal: IAEA chief 'confident' over early detection

The UN's nuclear watchdog, the IAEA, has a crucial role in policing the nuclear deal between Iran and six world powers.

It has to verify whether Iran cuts back its nuclear infrastructure and by the end of the year, the agency is expected to deliver a report on its investigation into suspicions that Iran carried out weapons design work - charges Tehran denies.

The head of the IAEA, Yukiya Amano, told the BBC's Bethany Bell that Iran has agreed to the agency's Additional Protocol, which gives his inspectors much more access to Iranian sites.