President Bush says Iran must suspend uranium enrichment activities if it wants to see an enhanced package of economic incentives.
Mr. Bush, speaking Thursday in a press conference with British Prime Minister Tony Blair at the White House, said the choice lies with the Iranian regime. He said Tehran for now has walked away from the negotiating table.
The president added it is "incredibly dangerous" to think of Iran with a nuclear weapon.
Mr. Blair said the West wants to resolve the Iranian nuclear standoff through multilateral institutions. He said Iran is a "great country," but needs to realize it must fulfill its international obligations.
Britain, France and Germany have proposed a package of incentives to try to persuade Iran to stop enriching uranium.
Foreign ministers from the five permanent U.N. Security Council members plus Germany are likely to meet next week in Europe to complete work on the package. Media reports say the package includes Western aid to build a light-water reactor in Iran for nuclear energy.
Punitive measures are also expected to be part of the talks. The U.S. favors sanctions if the incentive package fails to persuade Tehran to stop enriching uranium. Russia and China oppose sanctions and the use of force.
Western powers suspect Iran is planning to make a nuclear weapon -- a charge Tehran denies.