Iran's top nuclear negotiator said Tuesday that Tehran would halt all cooperation with the U.N. nuclear watchdog if the Security Council imposes sanctions against it, and warned it might go further and hide its nuclear program if the West takes any other "harsh measures."

Iran's top nuclear negotiator Ali Larijani, who is also Iran's Sercretary of Supreme National Security Council, shows evidence of Iran's agreement with France on Iran's nuclear activities before the 1979 Islamic Revolution, at a conference in Tehran, Iran, Tuesday, April 25, 2006. Larijani said Tuesday that Iran will withdraw from all cooperation with the U.N. nuclear watchdog agency if the U.N. Security Council imposes sanctions against it. [AP]

The statements by Ali Larijani were Iran's strongest statement of defiance yet before a Friday deadline the Security Council has given the country to stop all uranium enrichment. They came a day after Iran's president boldly predicted the Security Council would not impose sanctions on Tehran and warned he was thinking about dropping out of the Nuclear Nonproliferation Treaty.

"Military action against Iran will not end our program," Larijani said Tuesday, speaking at a conference on the energy program. "If you take harsh measures, we will hide this program. If you use the language of force, you should not expect us to act transparently."

He also said flatly that Iran would not abide by the Friday deadline to suspend uranium enrichment.

"If you take the first step wrong, the wrong trend will continue. We welcome any logical proposal to resolve the issue. They just need to say why should we suspend," Larijani said.

Iran's former President, Hashemi Rafsanjani, speaking at the same conference, claimed that Iran openly launched its nuclear program ¡ª which it insists is for peaceful energy purposes only ¡ª "but the behavior of Western countries forced it to carry out its nuclear program independently, based on local expertise and knowledge without relying on Western countries."

The International Atomic Energy Agency's chief spokesman, Marc Vidricaire, said Tuesday it would not comment on Iran's threat to scuttle all cooperation if sanctions are imposed. He said the IAEA planned no public statements ahead of agency head Mohamed ElBaradei's report to the Security Council and the agency's 35-nation board of governors, expected by the end of this week.

The United States, Britain and France maintain that Iran actually wants enriched uranium for atomic bombs, which would violate its commitments under the treaty. Iran denies the charge, but Washington is pressing fellow members of the Security Council to impose economic sanctions.

Meanwhile, an Israeli defense official said Israel was launching a satellite to spy on Iran's program, as Iran's leader persisted with his calls for the Jewish state's destruction.

Israel planned to launch from Siberia later Tuesday its Eros B satellite, designed to spot images on the ground as small as 27 inches, the defense official said. That level of resolution would allow Israel to gather information on Iran's nuclear program and its long-range missiles, which are capable of striking Israel, he said, speaking on condition of anonymity because of the sensitive subject matter.

On Monday, President Mahmoud Ahmadinejad called Israel a "fake regime" that "cannot logically continue to live." Last year, he called the Nazi Holocaust a "myth" and declared that Israel should be "wiped off the map."

Ahmadinejad's government insists the nonproliferation treaty gives Iran the right to enrich uranium for fueling civilian nuclear power plants, and he has given no ground in the international faceoff. The fiery hardline president said Monday he was reconsidering Iran's adherence to the treaty, which is aimed at stopping the spread of atomic weapons while allowing peaceful uses of nuclear energy.

"What has more than 30 years of membership in the agency given us?" he asked at a news conference, only the second since he took office last year at which foreign journalists have been allowed to ask questions.

As a member of the IAEA, Iran is obliged to honor the agency's basic nuclear safeguards agreement. However, that agreement is limited to select declared atomic facilities and programs.

It is not the first time Iran has threatened to curb cooperation: Several months ago, Tehran announced it would not honor the U.N. nuclear watchdog's so-called "additional protocol," which gave the IAEA increased and more thorough inspection powers.

Suspicions about Iran's intentions have grown since it was discovered in 2002 that Tehran had for two decades secretly operated large-scale nuclear activities that could be used in weapons making.

The IAEA says it has since found no direct evidence of an arms program, but it also says the Iranians have not been fully forthcoming in answering questions about their nuclear activities. After repeated attempts to resolve the issue through negotiations, the IAEA reported Iran to the Security Council for noncompliance.

Iran deepened international concerns by announcing April 11 that it had for the first time enriched uranium with 164 centrifuges ¡ª a step toward large-scale production of nuclear fuel.

The United States and others are urging the Security Council to take a tougher stance by imposing a mandatory order for Iran to halt enrichment, a move that would raise the threat of sanctions.

Russian and China, which are among the five permanent members that can veto council actions, have opposed that approach, saying diplomacy has not run its course. Ahmadinejad appears to be banking on their support to dissuade Washington from pressing a sanctions vote.