The radio commentary broadcast in Tehran today said Iranians will not accept an "unfair" decision.
Tehran has not issued its official reaction to the draft resolution, which was formally circulated to the full 15-member council late on July 28 and will likely be adopted next week. Statements by state radio are, however, often considered to voice the official line.
Tehran had previously objected to the resolution and says its nuclear program is aimed solely to generate electricity.
State radio also said the draft might not be approved because of opposition on the part of China.
The resolution was drafted after weeks of painstaking talks by Germany and the five Security Council members with veto power -- the United States, Britain, France, Russia, and China.
The draft resolution calls on Iran to comply with directives from the UN nuclear watchdog, the IAEA.
If Iran does not comply by August 31, the council would then consider adopting what the draft calls "appropriate measures," diplomatic language for possible sanctions.
U.S. Ambassador to the UN John Bolton said Iran had a clear choice: accept an international package of incentives offered in June -- or face sanctions.
Because of Russian and Chinese demands, the text is weaker than earlier drafts, which would have made the threat of sanctions immediate.
Russia's UN ambassador, Vitaly Churkin, was keen to make that distinction clear.
"To describe this resolution as a sanctions resolution is clearly misleading everybody about the purpose and the content of the resolution," he said.
The whole standoff has come about because Western powers suspect Tehran -- despite its denials -- is actually seeking to build nuclear weapons.
U.S. President George W. Bush said on July 28 that Iran would not be allowed to get its wish.
"My message is, 'Give up your nuclear weapons and your nuclear-weapons ambitions,'" he said.
What Would Sanctions Mean?
MOVING TOWARD SANCTIONS: If the United Nations Security Council imposes sanctions on Iran, domestic support for Iranian President Mahmud Ahmadinejad will wane, according to ALEX VATANKA, Eurasia editor for Jane's Information Group.
Vatanka told a February 24 RFE/RL briefing that "economic sanctions will hurt the average Iranian" and, consequently, many "will blame the ruling clerics" for making life difficult and "impairing the country's long term development."
Vatanka said sanctions would be a serious challenge to the Iranian government. If harsh economic sanctions were imposed, Iran's poorest population will be hurt the hardest -- and might react "as they did in the 1970s and protest in the streets." Sanctions on travel, Vatanka said, would hurt a many Iranians because "Iran is a nation of small traders" who depend on the ability to travel to earn an income. According to Vatanka, unemployment in Iran is estimated at 30 percent, "so small trading is essential to survival." Although current U.S. sanctions "haven't worked," he said, "Iranians fear an oil embargo." He stressed that "oil revenues are a major part of the economy, so it is critical to look at this sector."
Should negotiations with the European Union and the UN fail, Vatanka believes that Iran would follow a "North Korea model," since Ahmadinejad's base of support among the "Islamist militias" has been "urging withdrawal from the NPT [Nuclear Non-Proliferation Treaty]." The Iranian government's "tactic" so far, Vatanka said, is governed by the belief that "by shouting the loudest, you'll get concessions [from the West]."
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THE COMPLETE STORY: RFE/RL's coverage of the controversy surrounding Iran's nuclear program.