Germany, Britain and France said Thursday that nuclear talks with Iran had reached a dead end after more than two years of acrimonious negotiations and the issue should be referred to the Security Council.
However, the Europeans held back from calling on the 15-nation council to impose sanctions and said they remained open to more talks.
France said Friday that it favors a step-by-step approach with Iran over its nuclear program and that any sanctions request at this stage would be premature.
"We, like our partners, like the British and the Germans, consider that this co-request for sanctions is premature for the moment," Foreign Ministry spokesman Jean-Baptiste Mattei said.
Iran said that if it were confronted by the council, it would be obliged to stop cooperating with the U.N. nuclear watchdog, the International Atomic Energy Agency.
That would be, among other things, the end of random inspections, said Foreign Minister Manouchehr Mottaki.
"In case Iran is referred to the U.N. Security Council ..., the government will be obliged to end all of its voluntary cooperation," the television quoted Mottaki as saying.
Germany said Friday that talk of sanctions against Iran is "premature" until there are talks with other countries whose support would be needed for any U.N. measures.
Asked whether economic sanctions or specific resolutions against Tehran are currently an issue, Foreign Ministry spokesman Martin Jaeger told reporters: "We believe that is premature at the moment."
"I can say again in all clarity for the (German) government that we are counting on diplomatic means in dealing with Iran," Jaeger added.
The issue will be on the table when President Bush meets at the White House Friday morning with new German Chancellor Angela Merkel, reports CBS News correspondent Peter Maer.
Iran has been voluntarily allowing short-notice IAEA inspections since 2003. But last year it adopted a law requiring the government to block intrusive inspections of Iran's facilities if the IAEA refers the Iranian program to the council.