VIENNA: Talks between the U.N. nuclear watchdog and Iran this week appear not to have substantively advanced an investigation into suspected atomic bomb research by Tehran, potentially dimming chances for a broader deal between the Iranians and big powers.
Western officials say Iran must improve cooperation with United Nations nuclear sleuths if it wants to reach a settlement to a protracted dispute with six world powers over the country's nuclear program and be rid of crippling financial sanctions.
The International Atomic Energy Agency said in a statement after the Oct. 7-8 meeting in Tehran that discussions would continue. But it did not announce a date for the next round of talks focused on IAEA concerns that Iran had initially been supposed to address by late August.
Iran denies Western allegations that it is seeking to develop the capability to produce nuclear weapons, saying its atomic activities are aimed at generating electricity only.
Early last month, the IAEA said Iran had not answered questions by the Aug. 25 target date about alleged research activities into explosives testing and neutron calculations, which could be applicable to any attempt to make nuclear bombs.
In this week's meetings, "the two sides held discussions in relation to the implementation of the two practical measures relating to the initiation of high explosives and to neutron transport calculations," the IAEA said. "The agency and Iran will continue discussions on these measures."
The IAEA gave no further detail. But its statement suggested strongly that the Islamic Republic had still not fully implemented the steps it had agreed to carry out, answering questions about what the United Nations agency calls the "possible military dimensions" of Tehran's nuclear program.
It also said Iran had not offered new measures to comply with the investigation, more than a month after the IAEA asked it to do so.
Tehran's envoy to the Vienna-based U.N. agency, Reza Najafi, said the discussions had been "very constructive", according to Iran's ISNA news agency, which did not elaborate.
A diplomat in the Austrian capital said, however, that it seemed "very little progress" had been achieved.
The IAEA has for years been trying to get to the bottom of Western intelligence reports suggesting that Iran has worked on designing a nuclear warhead.
Iran has denounced the intelligence as fabricated, but has promised to work with the IAEA since last year when Hassan Rouhani, seen as a pragmatist, became president on a platform to overcome his country's international isolation.
It was not clear whether the IAEA's team that visited Tehran on Tuesday and Wednesday included an expert who on three previous occasions had not received a visa by Iran. Diplomatic sources said the official is believed to be an American nuclear weapons expert.
Rouhani's election raised hopes of a solution to the nuclear stand-off with the West after years of tension that raised fears of a new Middle East war. An interim accord was reached between Iran and six major powers - the United States, France, Germany, Britain, China and Russia - in Geneva last November.
But they fell short of a self-imposed July target date for a long-term accord and now face a new deadline of Nov. 24. The top U.S., Iranian and European diplomats are due to meet in Vienna next week, with only some six weeks to go.
While the powers seek to limit the size of Iran's future nuclear program, and thereby extend the time it would need for any attempt to accumulate fissile material for a weapon, the IAEA is investigating alleged research and experiments in the past that could be used to make the bomb itself.
A U.S. security institute said late on Wednesday it had located via satellite imagery a section of a sprawling Iranian military complex where it said an explosion or fire might have taken place earlier this week.
Iran's official IRNA news agency cited an Iranian defense industry body on Monday as saying that two workers were killed in a fire at an explosives factory in eastern Tehran.
An Iranian opposition website, Saham, described the incident as a strong explosion that took place near the Parchin military base around 30 km southeast of the capital. It did not give a source and the report could not be independently verified.
The Institute for Science and International Security (ISIS) said it had obtained commercially available satellite imagery on which six buildings at Parchin appeared damaged or destroyed.
However, the images ISIS issued indicated the site of the possible blast was not the same Parchin location where the U.N. nuclear agency suspects that Iran, possibly more than a decade ago, conducted tests of possible relevance to developing nuclear triggers. Iran denies having done so.