Iran is scoffing at a joint U.S.-European initiative to persuade it to give up its pursuit of atomic weapons.

The United States recently said that it would join Britain, France and Germany (the European nations known as the EU-3) to offer Iran economic incentives to give up its pursuit of nuclear weapons, with the EU-3 pledging to support Tehran's referral to the U.N. Security Council for possible economic sanctions if diplomacy doesn't work.

Iran has repeatedly said that it would never accede to American and European demands that it give up its drive to complete a nuclear fuel cycle and dismantle its atomic infrastructure.

Moreover, despite promising the EU-3 in November that it would temporarily halt all nuclear work, the Islamic republic has worked to upgrade and advance its atomic facilities over the past four months.

With the U.N. and its nuclear watchdog, the International Atomic Energy Agency (IAEA), less than eager to confront Iran about its nuclear defiance, the United States and European nations face a challenge to stop Tehran's pursuit of atomic weapons.

Iran Has Upgraded Its Nuclear Programs Over the Past Months Iran has underscored its refusal to comply with the international pleas to give up its atomic programs by making significant improvements to its nuclear facilities.

Iran pledged in November to temporarily halt all nuclear work while negotiations with the EU-3 were ongoing.

But Iran violated the spirit of the deal by using the time between signing the agreement and the date it took effect to finish converting a reported 40 tons of uranium yellowcake into the gas needed to fuel enrichment, a key step in assembling atomic arms.

In the ensuing months, Tehran has refused to allow IAEA officials to perform a full inspection of a suspected nuclear facility at Parchin.

Meanwhile, Iran is now pouring the concrete foundation for a heavy-water nuclear reactor at Arak which the IAEA has asked it not to build. Significant quantities of plutonium, which can be used as the core of an atomic bomb, would be produced as a byproduct of operating the Arak reactor.

Showing that it expects the freeze on its atomic programs to be short-lived, Iran said in March that it wants to break seals the IAEA has placed on its nuclear facilities to test "essential" parts of machines for nuclear work.

Iran Has Repeatedly Said It Won't Give Up Its Nuclear Work Iran has frequently proclaimed its refusal to accede to Western calls for it to permanently end its nuclear programs.

This hard-line stance was ostentatiously illustrated one Friday in March as students gathered for prayers at Tehran University.

"We will definitely not stop our nuclear activities," read a banner over the students' heads, quoting the words of Ayatollah Ali Khameini, Iran's supreme leader. "It is our red line."

Iranian leaders reiterate this point almost daily in public statements, even though the future of Tehran's nuclear programs is ostensibly the central issue at question in the negotiations with the U.S. and the EU-3.

In the most recent bid to move the talks forward, the Bush administration announced that it would drop objections to Iranian membership in the World Trade Organization and consider releasing to Iran spare parts for civilian aircraft.

According to Iran, though, benefits offered by the Americans and Europeans cannot persuade it to give up its nuclear programs.

"Our [nuclear] rights cannot be exchanged for any economic incentives," Iranian Foreign Minister Kamal Kharrazi said at a recent news conference.

Iran Faces Possible U.S. Sanctions For Its Nuclear Defiance Despite Iran's categorical refusal to dismantle its atomic programs, the IAEA has so far refused to refer the Islamic republic to the U.N. Security Council, which could impose economic sanctions to slow Tehran's pursuit of nuclear weapons.

While the EU-3 now supports referring Iran to the Security Council should negotiations fail, some members of Congress have put forth legislation to tighten the United States' sanctions on Tehran.

Supported by a bipartisan array of senators and congressmen, the Iran Freedom Support Act would attempt to choke off funds that could be used for the Islamic republic's nuclear program by tightening existing sanctions on Tehran. It would also offer support to pro-democracy activists within Iran.

As Iran continues to signal its intention to pursue nuclear weapons, Congress remains focused on deterring Iran from that quest.