The US Secretary of State warned Iran yesterday that it risks United Nations action if negotiations with the EU over its nuclear programme do not progress.
Dr Rice said the United States had set no deadline on the Iran talks, but that they cannot go on forever. She added the Bush administration had not changed its view that the United Nations should step in to get tougher on Iran.
In Washington, President Bush said the Iranians needed to know that the free world was working together to send a clear message: Don't develop a nuclear weapon.
"And the reason we're sending that message is because Iran with a nuclear weapon would be a very destabilising force in the world," Mr Bush said.
"The Iranians need to get that message," Dr Rice said, adding that Tehran should know that "there are other steps" the international community can take.
Iran says its programme is for nuclear power, not weapons. In Tehran, President Mohammad Khatami said that no Iranian government would ever abandon the progress the country has made in developing peaceful nuclear technology.
