Iran's President Mahmoud Ahmadinejad says Iran is talking to Russia about building additional nuclear power reactors.
He also invited other countries and companies to bid to build new power plants.
The Bushehr reactor built by Russia opened earlier this year.
Ahmadinejad said Iran needs 20,000 megawatts of energy and Bushehr is supplying 1,000 megawatts so the country still needs 19,000 megawatts.
Bushehr increased operations Sept. 12 after more than a decade of delays, pumping out electricity at up to 40 percent capacity.
Iranian officials say the plant could begin full-power operations in December.
The launch of the plant has been delayed for more than a decade over technical and construction setbacks — and possibly by Russian efforts to use it as leverage in negotiations with Iran over its secretive nuclear program.
Although the West has been deeply suspicious of Iran's nuclear aims, Washington has dropped initial reservations over Iran's push for atomic reactors for energy and research.
Last October, U.S. Secretary of State Hillary Rodham Clinton made a clear distinction between Bushehr and other nuclear efforts — such as uranium enrichment — that Washington worries could lead to weapons production.
"Iran is entitled to the peaceful use of nuclear power," she said after speaking at a U.N. Security Council meeting. "They are not entitled to a nuclear weapons program."
Russia has promised to have full oversight of the nuclear fuel used in the plant.
The Bushehr project dates back to 1974, when Iran's U.S.-backed Shah Mohammed Reza Pahlavi contracted with the German company Siemens to build the reactor. The company withdrew from the project after the 1979 Islamic Revolution toppled the shah and brought hard-line clerics to power.
In 1992, Iran signed a $1 billion deal with Russia to complete the project. Work began in 1995 with a timetable to begin operations in 1999.
Earlier this year, foreign intelligence reports said the plant's control systems were penetrated by Stuxnet, a malicious computer software.
Associated Press writer George Jahn contributed to this report from Vienna.