MOSCOW - Russian Atomic Energy Minister Alexander Rumyantsev said Wednesday that an agreement with Tehran that would allow shipment of uranium to an Iranian nuclear power plant was close to being signed.

Rumyantsev said an agreement about the return of spent nuclear fuel to Russia from the Bushehr plant would be signed after examination by ecological experts, and "then, there will remain no obstacle to the delivery of nuclear fuel from Russia for the atomic power plant at Bushehr."

"The agreement about the return of spent nuclear fuel from Bushehr to Russia is completely ready, and it meets all international standards," he said.

Russian officials have said that fuel delivery would be tied to Iranian promises to ship all spent fuel back to Russia for reprocessing and disposal. Plutonium for use in nuclear weapons can be derived from spent fuel rods and the Russian arrangement was aimed at ensuring other countries that Iran would not be able to obtain fissile material for weapons.

The prospect of uranium being shipped to the Bushehr plant was likely to increase international tensions over the plant, which the United States contends is part of Iranian attempts to develop nuclear weapons.

Russia has pushed Iran to sign additional nonproliferation agreements with the International Atomic Energy Agency in order to allay fears of weapons development.

Gholamreza Aghazadeh, the head of Iran's atomic energy agency, said that Iran agreed with the need for an additional protocol.

"Iran's position is clear. We have said that the signing of the additional protocol is necessary," Aghazadeh said after a meeting with Rumyantsev in Moscow.

But while Iran is "favorably inclined" to the additional protocol, it wants to know exactly what requirements it will be obliged to fulfill by the IAEA, Aghazadeh said.

"We would like these requirements to be concrete, transparent and documented," he said, calling for closer cooperation between Tehran and the IAEA.

Both Aghazadeh and Rumyantsev suggested that Russia was looking closely at proposals to increase Iran's nuclear capacity by 6000 megawatts by 2020, in addition to the 1000-megawatt Bushehr plant.