The IAEA said in a recent report that it has made no headway in confirming whether Iran conducted research related to nuclear weapons in the past.

The Vienna-based nuclear agency has also been trying in vain to get more access to Syria, in order to verify whether a site bombed by Israel in 2007 was indeed a secret nuclear reactor under construction.

'We are very pleased with the agreed approach reflected here today in the discussions that we've had on this issue this week,' US ambassador Glyn Davies said.