The senior U.S. envoy to the International Atomic Energy Agency (IAEA) says Iran should "confess" to running a secret nuclear weapons program up until 2003.

Gregory Schulte (file photo)

Gregory Schulte told reporters in Vienna Friday that the United States is looking for an acknowledgment from Tehran that it had a clandestine nuclear program.  He also warned that Iran's leaders could choose to restart the weapons program.

Schulte was referring to a recent U.S. intelligence report that said Tehran halted its nuclear weapons program in 2003.  The report also said Iran continues to enrich uranium and will have enough for a nuclear weapon sometime between 2010 and 2015.

In Washington Friday, U.S. Secretary of State Condoleezza Rice said the United States is open to meetings with top Iranian officials.  But she said Iran must first comply with U.N. Security Council resolutions and suspend uranium enrichment activities.

On Thursday, Rice said differences remain among the U.N. Security Council's five permanent member countries, plus Germany, on the subject of implementing further sanctions against Iran.

Diplomats from the Council's veto-wielding members and Germany did not resolve their disagreements during a conference call.  They are attempting to finalize terms of a third U.N. sanctions resolution against Tehran.  U.S. officials have said there is no chance of submitting a new resolution before January.

The United States and its Western allies have accused Iran of attempting to develop nuclear weapons.  Tehran argues that its nuclear work is strictly for civilian purposes.   

Some information for this report was provided by AFP, AP and Reuters.