The report said the IAEA’s role in nuclear safety was being enhanced after Fukushima, but remained “hobbled by member states’ reluctance to commit to mandatory measures and provide adequate resources.”

The bulk of funding for the IAEA - which has more than 2,300 staff and has a mandate that covers inspections as well as supporting nuclear security and peaceful use of the atom - comes from Western member states on a voluntary basis.

However, a group of industrialised, mainly European states as well as Japan have resisted budget hikes for the agency at a time when government finances are reeling from debt problems.

The United States, its biggest financier, has increased contributions since President Barack Obama took office in line with his call for IAEA funds to be doubled in four years.

The IAEA’s regular budget for 2012 was 331.5 million euros.

Findlay said developing states such as China, India, Brazil and Russia should help out more since they have become wealthier.