VIENNA (Reuters) - Cyber attacks such as the Stuxnet computer worm could harm nuclear sites but Russia and Iran are paying "enough attention" to prevent any possible accident at Iran's Bushehr reactor, the U.N. nuclear chief said on Tuesday.
Yukiya Amano, director general of the International Atomic Energy Agency (IAEA), told Reuters the U.N. watchdog was watching developments and gathering information about Stuxnet with interest.
Russia has urged NATO to investigate last year's Stuxnet attack on the Russian-built Bushehr nuclear plant in Iran, saying it could have triggered a disaster on the scale of the Chernobyl reactor explosion in Ukraine in 1986.
"Stuxnet, or cyber attack as a whole, could be quite detrimental to the safety of nuclear facilities and operations," Amano, a soft-spoken veteran Japanese diplomat, said in an interview in his 28th-floor office in Vienna.
He acknowledged the IAEA had only limited knowledge about the computer worm, which some experts have described as a first-of-its-kind guided cyber missile.
He noted that Bushehr, which Iran says will start operating soon, had been built by Russia and would be operated by Iran.
"I think they are giving enough attention to prevent possible accidents caused by cyber attacks," Amano said.
For now, the IAEA was not calling for any delay in the reactor's start-up of operations, he said. "Countries concerned are giving considerable attention to this issue."
But Amano also said the IAEA was interested in holding a meeting of experts to discuss the issue of cyber attacks.
In Brussels last week, Dmitry Rogozin, Russia's ambassador to the North Atlantic Treaty Organization, said the virus had hit the computer system at the Bushehr reactor on Iran's Gulf coast.
Iran began fuelling Bushehr in August and officials have said the reactor will begin generating energy early this year, a delay of several months following the spread of the global computer virus, which is believed mainly to have affected Iran.
URANIUM STOCKPILE GROWING
Iranian officials have confirmed Stuxnet hit staff computers at Bushehr but said it had not affected major systems.
Security experts say it may well have been a state-sponsored attack on Iran's nuclear program that originated in the United States or Israel, which suspect Iran is seeking to develop nuclear weapons.
Iran denies the charge and says Bushehr is the first in a planned network of nuclear reactors designed to meet growing electricity demand and help it export more of its oil and gas.
Some experts say Stuxnet may also have been a factor in slowing down Iran's uranium enrichment activities at Natanz, which can have both civilian and military purposes.
Any delays in Iran's enrichment campaign could buy more time for efforts to find a diplomatic solution to its stand-off with world powers, even though talks in Geneva in December and Istanbul last month failed to bridge the gap.
But Amano said Iran's production of low-enriched uranium, potential bomb-making material if refined much further, was "continuing steadily" and its stockpile was growing.
A temporary halt in low-level enrichment in mid-November lasted only for a short period of time, he said.
He said the IAEA did not know whether Iran was seeking to develop nuclear weapons, but that it was concerned that some activities may have military links.
Refined uranium can be used as fuel for power plants but also provide material, if enriched further, for bombs.
"We have chosen our words very carefully and we have never said that Iran has nuclear weapon programs but we have expressed our concern over some activities that might have military dimension," Amano said.
"Since 2008 our Iranian partners have not agreed with us to clarify this issue. It is very unfortunate," he said.
(Editing by Paul Taylor)