Iranian government spokesman Gholam- Hossein Elham said on Monday that the West's demand that Iran suspend its nuclear activities is "illegitimate."
"The demand (for Iran) to suspend its peaceful nuclear activities is an illegitimate demand and ... is in contradiction to the Iranian nation's dignity," Elham told a weekly press conference.
His remarks came as representatives of the five permanent members of the UN Security Council -- Britain, the United States, France, China and Russia -- plus Germany are scheduled to meet in London on Monday to discuss further measures against Tehran's tough stance.
Iran insists it has the right under international law to enrich uranium to make fuel for nuclear power plants.
Iran, the world's fourth largest oil exporter, says it needs to enrich uranium as a peaceful, alternative energy source and has the right to do so under the nuclear Non-Proliferation Treaty (NPT).
However, the West has accused Iran of trying to produce nuclear weapons under a civilian cover, a charge denied by Tehran.
The UN Security Council adopted Resolution 1737 on Dec. 23, 2006, demanding Iran to "suspend all enrichment-related and reprocessing activities, including research and development, and work on all heavy water-related projects."
Iran has rejected the resolution as an "illegal measure" and vowed to continue the country's nuclear programs.