U.S. officials are warning Iran that time is running out for Tehran to respond to proposals by the EU and the Security Council to resolve the nuclear stand-off. Iran was given two weeks to reply before risking yet another round of sanctions. VOA's Sonja Pace reports from London.

U.S. officials say it's time Iran offers a serious response to EU and U.N. proposals.

The latest package of incentives was discussed July 19 in Geneva, in a closed door meeting that represented Iran, the five permanent members of the Security Council, (the P5), Germany and the European Union. Taking part for the first time was a senior American envoy, Undersecretary of State William Burns.

Greg Schulte (file photo)

Greg Schulte is the U.S. Ambassador to the U.N. in Vienna and the International Atomic Energy Agency, the IAEA.  Speaking with VOA in London, Ambassador Schulte said Iran's response at that meeting turned into a "meandering lesson in Iranian history and culture".

"We weren't there for a lesson," he said.  "The P5 was there to see if Iran was willing to negotiate seriously."

On the table were a series of proposals delivered to the Iranians by EU foreign policy chief, Javier Solana in June.

Schulte outlined some of the proposals. 

"We have offered Iran's leaders a very generous package that would give them access to state of the art technology for nuclear power plants, that would give them assurances of fuel supply, that would address some of the security issues that they've raised, that would allow for cooperation in areas of common interest like fighting  against narcotics," he said. "And, we've looked for a way to get them into those negotiations and we said we would be there."

A way to entice the Iranians into negotiating is the freeze-for-freeze offer, meaning Iran would freeze its uranium enrichment at current levels and the U.N. and EU would freeze their current levels of sanctions.  This period would last six weeks, to build confidence and allow for more substantive negotiations to begin.

The bottom line demand remains, however that Iran must actually suspend the enrichment of uranium, the nuclear fuel source that can be used for generating energy, but also for making nuclear weapons.

The United States has said it would not negotiate directly with the Iranians until they suspend uranium enrichment.  So, the presence of Undersecretary Burns at the Geneva meeting was widely seen as a shift in U.S. policy.

Not so, insists Schulte. 

"The reason why Undersecretary Burns went to this meeting was not a change in U.S. policy, but was rather to send a strong signal," he said. "It was to send a signal that we backed -- we supported the package that was put on the table."

Iran was given two weeks to respond to the latest proposals or face further sanctions.

The United States, the U.N. and the EU have already imposed a series of sanctions on Iran and are threatening more.

Iranian leaders continue to say they will not suspend uranium enrichment and on Wednesday President Mahmoud Ahmadinejad insisted Iran would continue its nuclear program. And yet Iran says it is ready to talk.

Many believe Iran is simply buying time, especially given the upcoming presidential election in the United States and a change in administration.

That would be a waste of time, says Schulte. "If they try to outwait us, if they try to just buy time, they're only going to buy continued sanctions and more sanctions," he said. "And, whoever goes into the White House on January 21st is not going to look favorably at an Iran that has spent six more months violating Security Council resolutions."

Iran has all along said it wants to develop nuclear power for peaceful means, to provide energy.  However, many in the international community believe Iran wants to develop nuclear weapons.