TEHRAN, Iran — Iran said yesterday that it is seeking bids for the building of two more nuclear power plants, despite international pressures to curb its program.

Ahmad Fayyazbakhsh, the deputy head of Iran’s Atomic Energy Organization in charge of power plants, said the plants would be light-water reactors, each with the capacity to generate up to 1,600 megawatts of electricity.

Each plant would cost up to $1.7 billion and take up to 11 years to construct, he told reporters during a news conference at his office.

The country has been locked in a bitter funding dispute with Russia, which is building Iran’s first nuclear power plant near the southern city of Bushehr.

Russia delayed the launch of the plant, which had been set for September, and refused to ship uranium fuel for the reactor last month as earlier planned, citing Iran’s payment arrears. Iranian officials denied any payment delays under the $1 billion contract, and accused Russia of caving in to Western pressure.

Iran is already building a 40-megawatt heavy water reactor in Arak, central Iran, based on domestic technology. It is also preparing to build a 360-megawatt nuclear power plant in Darkhovin, in southwestern Iran. Mr. Fayyazbakhsh said the two new plants would be built near Bushehr. He also said he planned to travel to Russia next week to try to ease tensions and get the first Bushehr plant back on track.

The bids for the two plants, which will expire in early August, have been published on the nuclear organization’s Web site. Iran has already negotiated with several foreign companies that have expressed interest in the new project, Mr. Fayyazbakhsh said. He declined to name the companies.

Under Iranian law, the nuclear organization has been tasked with providing 20,000 megawatts of electricity through nuclear power plants during the next 20 years.

The U.S. and some of its allies accuse Iran of secretly developing nuclear weapons — a charge Iran denies. Iran has insisted it has a right to develop enrichment and has pushed ahead with the process at a separate facility outside the central town of Natanz.

The U.N. Security Council last month voted to impose new sanctions on Iran as part of a second set of penalties in three months against Tehran over its refusal to suspend uranium enrichment.

Iran said today it has begun operating 3,000 centrifuges at its Natanz facility — nearly 10 times the previously known number — in defiance of the U.N. demands. America, Britain, France, and others criticized the announcement.