US Secretary of State Condoleezza Rice said on Saturday that there is no urgent need to impose sanctions on Iran over its nuclear program.
"Nobody has said that we have to rush immediately to sanctions of some kind," Rice said.
As for the Vienna meeting of the International Atomic Energy Agency's board of governors on Monday, Rice said: "After the board report, I think the (United Nations) Security Council will have to have a serious discussion about what the next steps will be."
Also on Saturday, the Washington Post reported that the United States, preparing to take Iran's case to the UN Security Council next week, is seeking a 30-day deadline for Tehran to halt its nuclear program and cooperate with international inspectors.
The newspaper quoted unidentified US and European officials as saying that they expected tough negotiations among the Security Council's 15 members and said much hinges on Russia.
Russian officials have spent the past several weeks trying to persuade Iran to freeze much of its nuclear infrastructure and transfer its most sensitive aspects to Russian territory.
Iran has expressed interest in a joint uranium-enrichment venture with Moscow but also wants to enrich uranium at home, which it says would be used for an energy program.