But the delay to the Bushehr reactor in southwestern Iran, now due to come into operation in October 2006, will do little to allay international concerns about Iran's atomic ambitions.

"One of the reasons that the project has faced delay is our precise attention to international standards" on safety and the environment, deputy head of Iran's Atomic Energy Organisation Asad Allah Saburi said on Sunday.

Another factor holding up the 1000 megawatt 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.

Saburi 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.

European interest

Saburi said Russia had agreed to build at least one more reactor at Bushehr and that two European countries had expressed interest in building some other plants.

Tehran has denied it is secretly
building nuclear weapons

"My message to the Europeans is... we are ready and we have to move towards implementation contracts," he said.

While fuel for the first Bushehr reactor will be provided by Russia under a 10-year supply agreement, Iran plans to produce its own nuclear fuel through sophisticated uranium enrichment plants in the future.

Saburi said Iran should be able to produce its own fuel in time for the completion of the second reactor at Bushehr.

US opposition

Bushehr, being built with Russian help despite strong US opposition, has seen its start date pushed back steadily from an initial target of 2003. Russian officials had recently said it would start operations in 2005.

Iran rejects US accusations that it is secretly developing nuclear weapons, but has said the same rules should apply to Israel as well.

It says that despite Iran's large oil and gas reserves it needs to generate 7000 megawatts from nuclear power by 2021 to meet rising electricity demand.

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.