"We hope, along with the United Nations Secretary General (Kofi Annan), and as Foreign Minister Philippe Douste-Blazy has said several times, that Iran will seize the offer made to it," said French Foreign Ministry spokeswoman, Agnes Romatet-Espagne.

"It is premature to speculate on what response it will give," she said, noting that Tuesday would be the deadline for Iran to reply to the June 6 proposal made by Britain, China, France, Russia, the United States and Germany.

The offer made to Teheran provides for nuclear and economic cooperation, such as the building of light-water nuclear reactors and support for Iran to join the World Trade Organization, on the condition that Iran suspends its uranium enrichment activities.

Iran had said it would give its reply on Tuesday to the six-nation package. But it put on a defiant face on Monday, with its supreme leader Ayatollah Ali Khamenei saying Tehran would press on with its nuclear work and a nuclear official declaring suspension of uranium enrichment "practically impossible."

"The Islamic Republic of Iran has decided to continue its path powerfully regarding the nuclear energy issue," the state television quoted Khamenei as saying on Monday.

"Bullying powers and the United States have imposed huge pressure on Iran while they know that Iran is not developing nuclear weapons," he added.

In another sign of Teheran's defiance, Deputy Director of Iran's Atomic Energy Organization (AEO) Mohammad Sa'eedi said Monday that suspension of uranium enrichment was "practically impossible" even though the UN Security Council had made such a demand.

"Considering the technical progresses made by the Iranian scientists in the nuclear ground, suspension of uranium enrichment has now turned practically impossible," local Fars news agency quoted Sa'eedi as saying.

The UN Security Council adopted a resolution last month urging Tehran to suspend by Aug. 31 all enrichment-related and reprocessing activities, including research and development, or face possible sanctions.

Iranian officials have rejected the UN resolution as having no legality and vowed to retaliate if sanctions are imposed on their country.

The chairman of the Iranian parliament's National Security and Foreign Policy Commission, Alaeddin Boroujerdi, warned Monday that Iran might kick out International Atomic Energy Agency (IAEA) inspectors if it faces sanctions.

Meanwhile, Iranian officials confirmed that Tehran had finished considering the six-nation offer and would present its response on Tuesday.

Sa'eedi, the Iranian nuclear official, said Tehran's answer would be "very comprehensive and provide a very convenient opportunity for the West to move towards solving the case through negotiations."

Iran would not propose any parallel or counter plan to replace the six-nation package, he added.

Sa'eedi also announced that Iran's giant heavy-water project will become operational in the near future, saying that the achievement will make Iran the ninth country to own a heavy-water production complex in the world.

The IAEA has asked Iran to reconsider its plans to work on the heavy water research reactor at Arak, 230 km south of Tehran.

Iranian Foreign Minister Manouchehr Mottaki, who is on a visit to South Africa, said on Monday that he hoped a comprehensive agreement could be reached.

"We hope there is some cooperation and negotiation respecting the right of Iran to have nuclear technology and remove any questions," Mottaki said in Pretoria, South Africa's capital.

U.S. President George W. Bush warned Iran on Monday that the UN Security Council would move quickly to impose sanctions if Tehran decided to ignore the UN resolution.

When asked if he is confident that the Security Council will move quickly on sanctions if Tehran ignores the UN resolution, Bush said:" I certainly hope so."

The United States has accused Iran of secretly developing nuclear weapons under a civilian front, a charge categorically denied by Tehran which says that its nuclear program is for peaceful purposes.