Bush "stressed the importance of preventing Iran from obtaining nuclear weapons" including efforts currently underway in the United Nations Security Council.

McClellan said the two leaders agreed to continue to their dialogue on the issue.

Diplomats from the five permanent Council members and Germany were to meet in Paris Tuesday and again at the foreign ministers level in New York on May 9, following up on an International Atomic Energy Agency (IAEA) report confirming that Iran has not complied with demands to freeze uranium enrichment.

The United States and Europe are hoping a reluctant Russia and China will agree to a robust UN resolution that legally obliges Iran to halt the work to make reactor fuel, which can also be used for the core of an atom bomb.