The United States has called on the United Nations Security Council to impose sanctions on Iran because of its nuclear activities.
Wednesday in Vienna, U.S. envoy Gregory Schulte told a meeting of the board of governors of the International Atomic Energy Agency that the time has come to back diplomacy with international sanctions.
He said the action is necessary considering what he described as Iran's history of deception, lack of transparency, provocative behavior and disregard for its international obligations.
But three key European nations - Britain, France and Germany - called on Iran to suspend uranium enrichment activities to avoid sanctions.
Iran ignored an August 31 U.N. deadline to stop the enrichment of uranium, which can be used to make nuclear weapons.
Also Wednesday, a European Union spokeswoman announced that a meeting planned for Thursday between the European Union's foreign policy chief and Iran's top nuclear negotiator has been postponed.
The spokeswoman said that now only the aides to Javier Solana and Iran's Ali Larijani will meet in Paris.
The United States and other Western nations have accused Iran of enriching uranium for a secret nuclear weapons program. Tehran says its nuclear activities are for peaceful, civilian purposes.
Some information for this report was provided by AFP, AP and Reuters.