Russia says it will continue helping Iran construct an $800 million nuclear reactor and perhaps even assist in building another. This assistance has been strongly criticized by the United States, which has expressed concern Iran will use the reactor to develop nuclear weapons.
Russia's atomic energy minister has brushed aside U.S. criticism, saying its assistance to Iran is well within international regulations.
Alexander Rumyantsev says the power plant at Bushehr is only for civilian purposes, a point disputed by the Washington.
Russia and Iran signed a nuclear energy cooperation agreement in Tehran Wednesday, calling for the completion of the Bushehr plant and feasibility studies for possible construction of a second reactor.
The United States asks why Iran would need a nuclear plant given its vast reserves of oil.
The reactor is due to come on line next year and is under the supervision of the IAEA, the international body which oversees nuclear power.
Earlier this month the United States said two other nuclear sites being built in central Iran might also be capable of manufacturing nuclear warheads.