"More importance should be attached to the diplomatic track," Ambassador Wang Guangya said, adding that he doubted "if it is right moment for the Security Council to take more measures in the sanctions area."

The council has imposed two sets of sanctions on Tehran for its refusal to suspend uranium enrichment work, which major Western nations believe is a cover for bomb-making.

Ambassador Wang said senior foreign ministry officials of the five permanent council members with veto power - the United States, Britain, France, Russia and China - plus Germany had had telephone conferences but no decision had been made.

Still, the United States has considered tougher sanctions, such as the inspection of cargo from Iran for any illicit shipments. Britain has advocated denying landing and transit rights for Iranian airlines and ships and freezing assets abroad of some Iranian banks.

Iran currently is reviewing a "time out" or pause proposal to stop its enrichment in return for a halt to further UN sanctions. But so far Tehran has refused such a step, arguing that its nuclear work is for peaceful purposes only.

Iran's chief nuclear negotiator Ali Larijani and the European Union foreign policy chief, Javier Solana, have reviewed a proposal for a pause but no results were reported.

Mohamed ElBaradei, director of the International Atomic Energy Agency, had earlier proposed a "double suspension" involving a complete end to enrichment and lifting UN sanctions at the same time. 

This too has not yielded a positive response from Tehran, but ambassador Wang said that the council should take no action, or even draft a resolution imposing more penalties. He also said it would be helpful if "other parties who have a direct interest in finding a solution to this issue" entered in direct negotiations with Iran.