Iran's deputy foreign minister says the country is prepared "even for war" if the row over its nuclear weapons programme is not resolved.
And the country's president Mahmoud Ahmadinejad has also warned there will be "no brake, no reverse gear" on nuclear fuel work.
At a conference in the central Iranian city of Isfahan, minister Manouchehr Mohammadi told the gathered audience: "We have prepared ourselves for any situation, even for war."
"If they (the United Nations) issues a second resolution, Iran will not respond and will continue its nuclear activities," he said.
Meanwhile, President Mahmoud has remained defiant in his country's defence over nuclear technology.
"Iran has obtained the technology to produce nuclear fuel and Iran's move is like a train ... which has no brake and no reverse gear," he said in a presidential address in Tehran.
The UN issued sanctions on Iran in December over its nuclear work, which the West fears is aimed at building atomic weapons.