"If we're unable to make progress with the Iranians, we want to work together to implement new sanctions through the United Nations," Bush told reporters at a joint press conference with outgoing British Prime Minister Tony Blair.

The United States and Britain would "continue to make it clear that Iran with a nuclear weapon is not in the interest of peace in the world," Bush said.

Shortly after Bush spoke, a senior Iranian official told the semi-official news agency Mehr that Iran installing 3,000 centrifuges at its uranium enrichment facility at Natanz, which could allow it to process enough nuclear material to build one atomic bomb per year.