Iran has announced that Russia's state nuclear power company will construct two more reactors at the Bushehr nuclear power plant.
Behrouz Kamalvandi, spokesman for Iran's Atomic Energy Organization, said he expects the deal will be signed with Russian company Rosatom later this week.
Kamalvandi said the two new units should start operation within five to six years.
Rosatom chief Sergei Kiriyenko said on June 23 that he expects work to start on the two new reactors before the end of this year.
Iran commissioned the Bushehr plant, its first and only nuclear power plant, in September 2011.
German companies started construction of Bushehr in 1975 but abandoned the project after the Islamic Revolution in 1979.
Kiriyenko has said it would be easier to build new reactors and plants for Iran since Rosatom would not have to adapt its technology and equipment.