Iran has agreed to allow International Atomic Energy Agency (IAEA) officials access to the Arak nuclear reactor site after blocking visits by the UN watchdog for over a year.

Diplomats in Vienna say that Iran has also allowed an upgrade of the IAEA monitoring at Natanz, a uranium enrichment site. According to the IAEA much of the production at Natanz occurs out of the range of the surveillance cameras and the agency had difficulty keeping track of the expanding activities.

Iran, which insists its nuclear programme is only aimed at power production and peaceful scientific research, says the Arak complex will be geared towards producing isotopes for medical care and agriculture.