VIENNA  - Iran has installed hundreds more centrifuges that could enable it to enrich uranium faster since May, a UN atomic watchdog report showed Wednesday, as long-stalled talks were due to resume.

“Iran has continued to install IR-2m centrifuges in one of the units” at the Natanz site, the International Atomic Energy Agency said in its quarterly report, seen by AFP.

The Islamic republic now has 1,008 high-tech IR-2M centrifuges, up from 698 cited in the IAEA’s last report in May.

These were however “ under vacuum”, the report said.

The IR-2 centrifuges are of particular concern as they would allow Tehran to enrich uranium at a faster rate, allowing it to obtain the amount of fissile material needed for a nuclear bomb more quickly, if it wished to go down that path.

Western countries suspect Iran is trying to develop an atomic bomb but Tehran insists its nuclear programme is solely for peaceful purposes.

Earlier Wednesday, the IAEA said that talks with Iran over its controversial nuclear programme would resume on September 27. The talks were held up by presidential elections in Iran in June.

“To restore international confidence in the exclusively peaceful nature of Iran’s nuclear programme, it is essential that the structured approach enable the Agency to conduct... those verification activities that it considers necessary,” the report said of the upcoming talks.

Parallel talks between Tehran and the six powers — the so-called P5+1 composed of the United States, Russia, China, Britain, France and Germany — have also been stalled since April.

The international community fears that Iran is seeking to enrich uranium to levels of purity that would be required for a bomb.

Tehran has so far produced 372.5 kilogrammes of 20 percent-enriched uranium, up from 324 kilogrammes in May, the report said.

With part of this converted further for fuel purposes, this leaves however 185.8 kilogrammes — still under the 240-250 kilogrammes that experts say would be necessary for one atomic bomb.

Iran has been hit by four rounds of UN sanctions, as well as EU and US sanctions on its oil and banking sectors. The UN Security Council has also passed several resolutions urging it to halt enrichment.

Western powers hope however that Iran’s new president Hassan Rowhani, who replaced the firebrand Mahmoud Ahmadinejad, could breathe new life into efforts to resolve the nuclear issue.

On August 6, he said Iran was ready for “serious” talks on its nuclear programme without delay.

During his role as Iran’s chief nuclear negotiator from 2003 to 2005, Rowhani accepted the suspension of the enrichment programme.

An international official close to the dossier said the agency would be “anxious to see” how negotiations will be carried out under the new president and “how that is going to affect” talks.

The report by the IAEA’s director-general Yukiya Amano comes ahead of a meeting of the watchdog’s 35-member board of governors on September 9-13 in Vienna.

The previous discussions between the two parties date to mid-May, before the election of current Iranian President Hassan Rowhani, who was Tehran’s chief nuclear negotiator under reformist president Mohammad Khatami in the early 2000s.

Such a move is normally one of the last steps before the machines start spinning uranium gas into the material that can be used either as reactor fuel or as the core of nuclear warheads, depending on its enrichment level.

Iran says it is enriching uranium only for peaceful purposes and does not want nuclear arms. Iran already is running more than 15,000 older machines.

The new centrifuges are three to four times more effective.