"The fact is the Iranians change their stories to fit the facts," US ambassador to the International Atomic Energy Agency Kenneth Brill told reporters as the IAEA's 35-nation governing board met in Vienna to discuss Iran's nuclear program.
IAEA chief Mohamed ElBaradei said Monday that the watchdog would continue probing charges Iran is secretly developing nuclear weapons despite Tehran's insistence that the investigation end as it has fully disclosed its atomic activities.
Brill said: "This board has a lot more work to do and I expect will be dealing with the Iranian issue for many boards to come," referring to the regular meetings held at IAEA headquarters in Vienna every three months.
He said ElBaradei's report on Iran ahead of the current meeting "makes it clear that there are a large number of very significant issues that still need to be dealt with."
ElBaradei told the IAEA board Monday that a declaration by Iran on its nuclear program last October "did not include any reference to its possession of P-2 centrifuge designs (for making enriched uranium which could be weapon-grade) and related RD (research and development) which in my view was a setback to Iran's stated policy of transparency."
ElBaradei said "this was particularly the case" since the October declaration was trumpeted by Iran as providing "the full scope of Iranian nuclear activities" including "a complete centrifuge R and D chronology."
Brill said senior Iranian officals had said the October report would be "full, complete and represent total transparency."
"When it was proved that was not the case, that the Iranian declaration was neither correct nor complete in very significant ways" then the Iranians "changed their story and said we didn't mean it was going to be full and complete," Brill said.
Iran's ambassador to the IAEA Pirooz Hosseini told reporters Tehran did not say everything in a report last October "because what we announced at that time was based on our obligations under the safeguard agreement" of the nuclear Non-Proliferation Treaty (NPT).
In December, Iran signed an additional protocol to the NPT allowing for wider inspections and Hosseini said that "according to the time line of the additional protocol, we are going to provide every information which is necessary for the agency."