Asked how Iran would respond if the Council adopted a tough resolution drafted by Britain and France, foreign ministry spokesman Hamid Reza Asefi said that Iran "will certainly reject it and cannot carry it out".
"We will not accept any resolution that is against our rights," he told reporters, adding that "a suspension and pause (of enrichment) is not on the agenda at all."
The two European powers, backed by the United States, have asked the Security Council to approve a text legally requiring Iran to freeze all uranium enrichment and reprocessing activities.
Iran says it only wants to enrich uranium to make nuclear fuel, though the process can be extended to make weapons.
"Any action by the Security Council will have a negative influence on our cooperation with the agency," Asefi told reporters, repeating Iran's threat to halt International Atomic Energy Agency (IAEA) inspections.
"The involvement of the Security Council will direct the path of cooperation towards confrontation," he said, warning that the Security Council would not be able to enforce its demands.
"It's obvious that the Security Council should not take any action that it is not capable of dealing with later, because we will not refrain from our rights," Asefi said.
Iran's hardline President Mahmoud Ahmadinejad also signalled Iran could quit the nuclear Non-Proliferation Treaty (NPT) if tensions worsened.
"If the signature of a treaty threatens the rights of a nation, it has no validity for that nation," the ISNA news agency quoted him as telling members of Iran's Basij militia.
Iranian leaders have already signalled Iran could quit the NPT -- the cornerstone of the global effort against the spread of nuclear weapons.
Iran argues nuclear fuel work is authorised by the NPT, but the country is accused of seeking to exploit this loophole in the treaty.
The hardline-controlled parliament also stepped in by warning it could force the government to definitively put an end to tough IAEA inspections and leave the NPT.
Iran also rejected a call from UN Secretary General Kofi Annan for Washington to enter direct talks with Iran over its nuclear programme.
"It's obvious that all these artificial crises have been created by the US, which is against Iran's independence. So there is not need to have the US in these talks," Asefi said.
"The US is not ready for equal dialogue. They want to have others on their side through intimidation."
Washington has not had diplomatic relations with Iran since 1980 after the seizure of the US embassy in Tehran in 1979 in which 52 Americans were held for 444 days.