Iran on Sunday announced a further substantial delay in the long overdue project to complete its first nuclear power plant, part of a programme which Washington says could be used to make atomic arms.
But the delay to the Bushehr reactor in south-western Iran, now due to come onstream in October 2006, will do little to allay international concerns about Iran's atomic ambitions which focus more on its uranium enrichment efforts.
Bushehr, being built with Russian help despite strong US opposition, has seen its start date pushed back steadily in recent years from an earlier target of 2003. Russian officials had recently said it would start up in 2005.
"One of the reasons that the project has faced delay is our precise attention to international standards" on safety and the environment, Asadollah Sabouri, deputy head of Iran's Atomic Energy Organisation, told a news conference.
Another factor holding up the 1,000 MW plant is the failure to agree on a contract to return spent fuel to Russia. The agreement is designed to ease fears that Iran could reprocess the spent fuel and turn it into bomb-grade material.
Sabouri said Iran and Russia had yet to agree on the cost and procedures for returning the spent fuel, but said both sides were committed to reaching a deal.
Iran rejects US accusations that it is secretly developing nuclear weapons. It says that despite its large oil and gas reserves it needs to generate 7,000 MW from nuclear power by 2021 to meet rising electricity demand.
Sabouri said Russia had agreed to build at least one further reactor at Bushehr and that two European countries had expressed interest in building some other plants.
"My message to the Europeans is... we are ready and we have to move towards implementation contracts," he said. He declined to name the countries.
While fuel for the first Bushehr reactor will be provided by Russia under a 10-year supply agreement, it is Iran's plans to produce its own nuclear fuel though sophisticated uranium enrichment plants that has proven most controversial.
Tehran kept its uranium enrichment facilities secret until 2002. Low-grade enriched uranium is used as fuel in power plants but highly-enriched uranium is used to make bombs.
Sabouri said Iran should be able to produce its own fuel in time for completion of the second reactor at Bushehr.