Ali Akbar Salehi, the head of Iran's Atomic Energy Organization, said his team has chosen the location and made construction plans for 10 new uranium enrichment plants.
"The construction of one of these facilities will begin by the end of the (current Iranian) year (March 2011) or start of the next year," he told the Islamic Republic of Iran Broadcasting network.
The Natanz nuclear facility is enriching uranium to a level of 20 percent, he added.
The U.N. Security Council in June imposed new sanctions on Iran as punishment for its controversial nuclear program.
Washington and the European Union followed suit with unilateral sanctions in July that target Iran's energy sector.
Western allies worry Iran is developing the technology needed to develop a nuclear weapon. Tehran insists its nuclear program is for civilian energy.
Officials in Moscow last week said engineers would push the start button Saturday at the Bushehr nuclear power plant in Iran.
Moscow has worked with Tehran on construction of the Bushehr power plant since the 1990s. Russian atomic energy corporation Rosatom will operate the plant, supply the fuel and remove any nuclear waste.