"The adoption of another resolution is not welcome but is not worrying," Iran's government spokesman, Gholam Hossein Elham, told reporters. "It will not affect our work and will not concern our people."

President Mahmoud Ahmadinejad brushed off warnings from inside and outside Iran that the passing of a second United Nations Security Council resolution against Tehran would put the country in an increasingly dangerous situation.

"Those who say that this country is in a critical situation just think they are politicians," Ahmadinejad told the government daily Iran in an interview.

"Where is our country in a critical situation? Which part of our country is in a critical condition?" he asked in the interview, the full text of which will be published on Thursday.

Proceeding with caution

The defiant remarks by the government come after Ahmadinejad's reformist predecessor Mohammad Khatami warned on Monday that Iran should act with caution and even compromise to prevent the adoption of a second UN resolution.

The Security Council's five permanent members -- Britain, China, France, Russia and the United States (P5) -- plus Germany made "substantial progress" on Monday towards agreeing the new draft resolution tightening sanctions against Iran, said Emyr Jones Parry, Britain's UN ambassador.

German Ambassador Thomas Matussek said: "I find it a very encouraging experience that the six tried to work together in a very constructive and forward-looking way, and that signals that the Security Council ... is together, because we need that in order to get Iran back on the negotiating track," he said.

"That is what we want. It's not punishing, it's not harming Iran, but to get them back on track and to help them find a way out of their self-imposed isolation," the German envoy added.

Progress report on Tuesday

Jones Parry said the P5 would be able to report their progress to the Security Council's 10 non-permanent members on Tuesday.

The P5 plus Germany are considering new punitive measures, including a travel ban on officials involved in illicit nuclear work, an arms embargo as well as financial and trade restrictions, to tighten sanctions adopted by the council last December in the face of Tehran's nuclear defiance.

The six powers have, however, offered to suspend their sanctions against Iran if Tehran complies with UN demands, particularly by suspending its sensitive nuclear fuel work.

Tehran has so far refused to halt its uranium enrichment program, which the West fears is a cover for producing nuclear weapons. It insists its goal is simply to provide fuel for electricity generation.