Iran intends to continue expanding its civilian nuclear energy program despite U.S. allegations that it is a cover for a secret nuclear weapons program, a senior Iranian official said today.

Javad Zarif, Iran's ambassador to the United Nations, said his government has no intention of developing nuclear weapons but that it would seek to aggressively develop its nuclear power industry because of fears the United States may persuade foreign suppliers, including Russia, China and Ukraine, to stop shipments of nuclear components to Iran.

"You don't expect Iran to sit still," he said in an interview at the Iranian mission to the United Nations. "We don't have any confidence that two years down the road, three years down the road, the pressure by the United States may or may not work on our suppliers. We have to create a source of self-sufficiency, which will include a fuel cycle program."

The Bush administration has said it suspects Iran is enriching uranium for nuclear weapons at a facility near the town of Natanz in central Iran. The existence of the nuclear facility was made public in August by an Iranian opposition group, the National Council of Resistance of Iran. U.S. officials assert that when the project is completed in 2005, it will be capable of producing several nuclear bombs a year.

Zarif denied the charge. He said Tehran did not initially disclose its efforts to develop the Natanz nuclear "fuel cycle" plant because of concerns the United States would pressure foreign suppliers to withdraw from the project.

But he insisted that Iran's representative to the International Atomic Energy Agency informed the nuclear watchdog of the country's nuclear activities in June, more than a month before the facility's existence became public. A spokesman for the Vienna-based IAEA, reached by telephone tonight, said he could not immediately confirm the Iranian envoy's claim.

"We have nothing to hide; we played a very straightforward, transparent game with the IAEA," Zarif said. "If the United States did not follow this policy of simply trying to deny Iran access to nuclear technology for any purpose, I don't think you would have had all these scenarios that we are confronting. Unless the United States changes its behavior, we will see more of the same."

As a signatory to the nuclear Non-Proliferation Treaty, Iran is permitted to develop nuclear energy under the supervision of the IAEA. Under the terms of the agreement, Iran is allowed to enrich uranium. It is under no legal obligation to declare the facility until it began enriching uranium.

"The United States does not believe in the IAEA," Zarif said. "The United States wants Iran not to have nuclear power, period."

The IAEA's director general, Mohamed ElBaradei, visited Natanz on Feb. 21. He found a fully operational plant with 160 gas centrifuges for enriching uranium. When completed, the facility is expected to hold 5,000 centrifuges, enough to produce at least two nuclear bombs a year. The discovery has prompted the agency to renew pressure on Iran to sign a 1997 protocol that would allow international inspectors greater authority to conduct inspections on short notice and to take advanced environmental sampling. Iran has declined to ratify the protocol.

The IAEA board of governors is expected to review a report on the agency's investigation into the Iranian facility. "I believe once this report is out, it will be clear that all these fictions . . . will prove to be untrue," Zarif said.