TEHRAN: The head of the UN nuclear watchdog said Sunday there is a “shifting of gears” in Iran’s confrontation with the West to more cooperation and transparency and he announced that international inspectors would visit Tehran’s newly revealed uranium enrichment site on Oct. 25.

The International Atomic Energy Agency chief Mohamed El-Baradei, speaking at a news conference in Tehran with Iran’s top nuclear official, said his agency “has no concrete proof of an ongoing weapons program in Iran.” But the IAEA has “concerns about Iran’s future intentions,” he said.

“I see that we are at a critical moment. I see that we are shifting gears from confrontation into transparency and cooperation,” said El-Baradei.

His visit followed a week of intense diplomatic activity surrounding Iran’s nuclear program, set off by the revelation that Tehran had been secretly constructing a new uranium enrichment plant just north of the city of Qom.

On Thursday, Iran and six world powers put nuclear talks back on track at a landmark session in Geneva that included the highest-level bilateral contact with the US in years.

President Barack Obama’s national security adviser said Sunday that Washington was also pleased with the level of cooperation from Iran.

“For now, things are moving in the right direction,” James Jones said on CNN’s “State of the Union” program.

El-Baradei arrived Saturday to set up the UN inspection of the Qom facility.

The revelation of the plant heightened suspicion that Tehran is using a civilian nuclear program as a cover for developing weapons. Iran denies that and says its nuclear program is for peaceful purposes only.

“It is important for us to send our inspectors to do a comprehensive verification of that facility, to assure ourselves that it is a facility that is built for peaceful purposes,” El-Baradei said, seated beside Ali Akbar Salehi, the head of Iran’s nuclear agency.

“We agreed that our inspectors would come here on the 25th of October to do the inspection and to go to Qom and I hope and I trust that Iran will be as transparent with our inspectors team as possible.”

The US ambassador to the United Nations said that the permanent members of the UN Security Council are studying options for more sanctions if Iran does not prove its nuclear work is for peaceful purposes only.

Ambassador Susan Rice, speaking on NBC TV’s “Meet the Press,” also cautioned that Iran had a “finite period” to completely open its nuclear program to international inspections. She refused to set a deadline.

Iranian President Mahmoud Ahmadinejad told El-Baradei that Iran’s cooperation with the agency has left no ambiguity over Tehran’s nuclear activities.

“Outstanding issues were resolved due to good cooperation between Iran and the agency,” state TV quoted Ahmadinejad as saying. “Today, there are no ambiguous issue left.”