MOSCOW, Dec. 17 (UPI) -- Iran has received its first uranium from Russia for use in the joint nuclear power plant being built in Bushehr, Russian officials said Monday.

The site isn't due to go into operation until sometime in 2008 and the Russian Foreign Ministry's Web site said Iran has signed guarantees the fuel can only be used at and for the Bushehr plant. Iran also agreed to return spent fuel to Moscow for processing, CNN reported.

The plant is being built under the oversight of the United Nations' International Atomic Energy Agency, and Sunday's initial delivery was six months ahead of when it would be needed "as stipulated by technical requirements," the Russian ministry statement said.

Iran is under U.N. sanctions for uranium enrichment activities at its other plants, which numerous governments are concerned is part of a nuclear weapons program. Iran insists it is only for the generation of electricity and claims it's program is full transparent to IAEA inspectors.