Technical problems are slowing down Iran's uranium enrichment, allowing more time for diplomacy to defuse tensions over its nuclear programme, a former official with the UN atomic watchdog said.
"It looks like that there might be still time for a negotiation," said Olli Heinonen, former deputy director of the International Atomic Energy Agency (IAEA).
Iran has run into technical difficulties in its efforts to enrich uranium, due possibly to a flawed design for centrifuges, Mr Heinonen said on Monday at an event organised by the Arms Control Association.
The centrifuges are also operating at only 60 per cent of capacity and Iran for some reason has removed hundreds of the machines.
"This indicates there is a problem," Mr Heinonen said.
A September report from the IAEA said an enrichment facility at Natanz houses about 8,800 centrifuges, but only about 3,700 are operating.
Iran also has struggled with plans to build a new, more powerful centrifuge model, according to Mr Heinonen.
Iran's current centrifuges are drawn from a Pakistani model that was based on an old dutch design. But developing a new centrifuge may be hampered by difficulties in securing raw materials such as carbon fiber, due to tightened international against Tehran.
Reports of problems with Iran's centrifuges have fed speculation that the country's nuclear program may have been targeted for sabotage by the United States or its allies.
Computer security experts say an extraordinary computer worm, stuxnet, may have disrupted control systems for the Iranian centrifuges, causing them to spin wildly out of control.
Most of the stuxnet infections have been discovered in Iran, giving rise to speculation it was designed to disrupt the Islamic republic's nuclear work.
The United States reportedly has tried to derail Iran's enrichment efforts in the past, with the CIA arranging the supply of flawed parts to Iran for several years, according to The New York Times.
Stalled negotiations between world powers and Iran over Tehran's nuclear program are now likely to resume on December 5 in Geneva, according to the European Union's top diplomat, Catherine Ashton.