U.S. Secretary of State Condoleezza Rice says she hopes Iran will seriously consider a new package of incentives to suspend its nuclear activities.
The world's major powers agreed on the package Thursday in Vienna. It also includes United Nations Security Council action if Iran refuses to halt uranium enrichment and reprocessing.
In a series of interviews with American media, Rice said the five permanent members of the Security Council plus Germany are hopeful that Iran will respond within weeks once the offer is presented.
Russia and China have been opposed to threatening Iran.
But Rice told CNN television that "Russia and China have signed on to the two paths" approach of incentives and punishment.
Diplomats say Britain, France and Germany are expected to formally invite Iran to begin negotiations within days.
Before Thursday's meeting in Vienna, the U.S. offered to join European Union talks with Iran if it agrees to suspend its nuclear activities.
Iranian Foreign Minister Manouchehr Mottaki rejected the conditions for the talks, saying his country will not give up its right to enrich uranium.
The United States has not held direct, official talks with Iran since 1979.
The West suspects Iran is seeking to develop nuclear weapons -- a charge Tehran denies.