Iranian President Mahmoud Ahmadinejad Monday rejected as "illegal" a UN Security Council demand that requires Tehran to suspend its uranium enrichment work.
He said his country would continue its nuclear activities without any fear as they were "within international regulations", the state television reported.
Ahmadinejad said Tehran would not give in to pressures to stop its nuclear program.
"Mounting threats and pressures against Iran's peaceful nuclear activities won't cause even one iota of hesitation in the will of the Iranian nation to continue on this path (nuclear technology)," Ahmadinejad said.
"Iran won't be intimidated," he added.
The president also rejected UN Security Council sanctions against North Korea for conducting a nuclear test.
"Some western countries have turned the UN Security Council into a weapon to impose their hegemony, and issue resolutions against countries that oppose them."
The UN Security Council passed a resolution Saturday to impose sanctions on North Korea, and demanded that the country abandon its nuclear programme immediately.
The Council adopted a resolution late July, urging Tehran to suspend all enrichment-related and reprocessing activities by August 31, including research and development, or face international sanctions.
Despite Tehran's failure to meet the UN demand, EU foreign ministers decided in September to continue serious talks with Tehran in efforts to solve Iran's nuclear issue through diplomacy.