The U.N. nuclear monitoring agency said Friday that "recently received" information is adding to concerns Iran may have worked on developing nuclear arms.
At the same time, a report by the organization _ The International Atomic Energy Agency _ noted that Tehran continues to stonewall its attempts to follow up on that information, which points to possible experiments with components of a nuclear arms program.
The report also said conversion work of uranium ore to the gas from which enriched uranium is made remained idle for the 18th month, indicating a possible shortage of the raw material on which Tehran's nuclear program is built on.
A new intelligence report from an IAEA member country shared with The Associated Press says Iran is expanding its covert global search for raw uranium. It divulged a secret visit by Iranian Foreign Minister Akbar Salehi last month to uranium-rich Zimbabwe in search for the metal.
Iran denies any shortage, but the intelligence assessment is line with international assessments that Iran's domestic supplies cannot indefinitely sustain an expanding nuclear program.
An annex to Friday's confidential IAEA report listed "the outstanding issues which give rise to concern about possible military dimensions to Iran's nuclear programme." It included design work on a nuclear payload; experiments with explosives that could detonate such a payload and other work that could be linked to making weapons.
The list contained no new information, with much of its contents based on material that first surfaced seven years ago on a laptop United States intelligence agencies say was spirited out of Iran by a defector. A senior international diplomat familiar with the report said it was annexed to summarize suspicions for the 35-IAEA board member nations the report was meant for.
Still, the listing was unusual. Part of a longer annex of "areas where Iran is not meeting its (international) obligations," it also appeared to reflect IAEA frustrations that Iran has rejected its attempts to follow up on the allegations since August 2008.
New intelligence continues to come in to the agency strengthening those suspicions, despite Tehran's stonewalling, said the report, obtained by the AP.
"Based on the agency's analysis of additional information since August 2008, including new information recently received, there are further concerns which the agency also needs to clarify with Iran," said the report, which was also sent to the U.N. Security Council.
Tehran is under four sets of U.N. sanctions for its refusal to stop uranium enrichment _ which can create both nuclear fuel and fissile warhead material _ and other instances of nuclear defiance. It insists its program is peaceful and meant only to power a future generation of reactors.
Iran's enrichment work was stopped for a day in November, apparently by a Stuxnet virus attack suspected to have come from Israel or the United States.
Its total stockpile of low-enriched uranium nonetheless grew by more 400 kilograms (more than 800 pounds from October to a total 3,610 kilograms (almost 8,000 pounds) now. That is more than enough for two simple nuclear weapons, should Tehran decide to enrich to higher, weapons grade levels, and indicates that the cyber attack setback was temporary.
While the report did not specify how recent its new information was on possible weapons programs experiments, the senior international official said the agency received fresh intelligence within the last three months. He asked for anonymity because his information was confidential.
"Iran is not implementing a number of its obligations including ... clarification of the remaining outstanding issues which give rise to concerns about possible military dimensions to its nuclear programme," said the report.
"Iran is not providing the necessary cooperation to enable the Agency to provide credible assurance about the absence of undeclared nuclear material and activities in Iran, and therefore to conclude that all nuclear material in Iran is in peaceful activities."