The visit had been scheduled for this month but was put back to the second half of February because of an earthquake last month at Bam that killed some 30,000 people and left an estimated 75,000 others homeless, Nikolai Shingarev told the ITAR-TASS news agency.

The two sides are to "discuss accelerating the construction of the Bushehr power plant and a protocol on the return of spent fuel that could be signed at this time," Shingarev said.

Russia has made completion of the Bushehr nuclear plant conditional on Iran signing an undertaking to return the spent fuel.

The signature was due to take place last year but was postponed by Tehran on several occasions for "technical reasons."

On December 18, after strong Western pressure, Iran signed up to a Nuclear Non-Proliferation Treaty additional protocol providing for surprise UN inspections of its nuclear sites to fend of US accusations that it is preparing a nuclear weapons programme.

Shingarev said the Russian firm TVEL "has produced fuel that will be sent to the Bushehr plant after the signing" of the Moscow-Tehran accord on the return of spent nuclear fuel.

Iran last October agreed to make a full declaration of its nuclear activities and temporarily suspend uranium enrichment, though it stressed that the suspension was "provisional and voluntary."

Uranium enrichment is at the centre of international concern that Iran may be capable of building an atomic bomb. Tehran has said it reserves the right to restart enrichment "at any moment."

Russia has overridden strong objections from the United States to maintain its nuclear cooperation with Iran.

WAR.WIRE