Iranian President Mahmoud Ahmadinejad on Monday said additional UN sanctions would cause Iran to step up its nuclear development even further, Iran's state broadcasting company reported.
The UN Security Council has set a deadline of late May for Iran to halt its uranium enrichment program, warning it will gradually ratchet up punishment. The council imposed limited sanctions in December and strengthened them slightly last month because of Iran's refusal to suspend enrichment.
The enrichment process can produce fuel for nuclear reactors or - if taken to a higher degree - the material for atomic bombs.
"After the first resolution, we undertook the nuclear fuel cycle; after the second one, we began the industrial phase of nuclear fuel; and if another resolution is issued, new capabilities of the Iranian nation will surface," the broadcasting company's Web site quoted Ahmadinejad as saying in a speech in the southern city of Kazeroun.
The UN's latest sanctions ban Iranian arms exports and freeze the assets of 28 individuals and companies involved in Iran's nuclear or ballistic missile programs.
Iran has rejected the sanctions and announced a partial suspension of cooperation with the UN nuclear watchdog, the International Atomic Energy Association.
The Iranian president did not provide details on how the country would ramp up its development in response to a third set of sanctions, but his comments were yet another show of defiance to the international community's demands that Iran roll back its nuclear program.
Last week, Iran said it had begun operating 3,000 centrifuges at its Natanz facility - nearly 10 times the previously known number. The US, Britain, France and others criticized the announcement, but experts expressed skepticism that Iran's claims were true.
During Sunday's speech, Ahmadinejad reiterated that Iran would not back down from its right to pursue nuclear development and maintained the peaceful nature of the country's program.
The US and some of its allies accuse Iran of secretly developing nuclear weapons - a charge Iran denies.
"The Iranian nation will use all capacities of nuclear energy in agriculture, industry, medicine and generating electricity," he said.
Iran's defiance has heightened concerns in the region that the US or Israel could respond with a military strike against the country's nuclear facilities.
The US stoked these fears last month when it held a massive military exercise off Iran's coast that included two aircraft carrier groups, its largest show of force in the region since the 2003 invasion of Iraq.
US Chief of Naval Operations Adm. Michael Mullen attempted to quell concerns Monday by saying the US had no plan to attack Iran and the heightened naval presence was meant to reassure its regional allies.
"I'm aware of no plans that involve any kind of attack on Iran," Mullen told reporters in the Pakistani capital, Islamabad. "All efforts with respect to Iran, I believe, need to be handled through the diplomatic channels."