Tehran has since been seeking to ensure greater security for such sites.

The sprawling Natanz site includes a commercial-scale enrichment plant that is underground, which could offer some protection from any potential airstrikes.

“On 13 April 2022, Iran informed the Agency that the machines would start operating at the new workshop the same day,” the report said, without saying whether it had verified that the machines had started operating, suggesting it had not had access to the location since then.

UN watchdog installs new cameras

Also, the watchdog said it installed surveillance cameras to monitor the new centrifuge workshop.

The start of work at the new workshop comes after Iran’s centrifuge facility in Karaj found itself targeted in what Iran described as a sabotage attack in June. Natanz itself has twice been targeted in sabotage attacks amid uncertainty over the nuclear deal, assaults that Tehran has blamed on Israel.

The Vienna-based International Atomic Energy Agency said it installed cameras and removed seals from machines at the workshop on Tuesday. Those machines will be used to make centrifuge rotor tubes and bellows, crucial parts for the devices that spin at very high speeds to enrich uranium gas.

On Wednesday, “Iran informed the agency that the machines would start operating at the new workshop the same day,’’ the IAEA said in a statement.

Natanz became a flashpoint for Western fears about Iran’s nuclear programme in 2002, when satellite photos showed Iran building an underground facility at the site, some 200 kilometers (125 miles) south of the capital, Tehran. Iran long has insisted its nuclear programme is for peaceful purposes. However, US intelligence agencies and the IAEA believe Iran had an organised military nuclear programme up until 2003.

In July 2020, Natanz found itself targeted in sabotage that blew up a centrifuge assembly building. In April 2021, a sabotage attack in its underground halls destroyed centrifuges. Iran since has begun building a new extension to Natanz in a nearby mountain, likely to further harden the site.

Israel, also suspected in the killing of a scientist who found Iran’s nuclear military programme, has hinted it carried out the Natanz attacks.

The camera installation comes as efforts to restore the nuclear deal, which saw Tehran limit its enrichment for the lifting of economic sanctions, appear deadlocked over an Iranian demand for America to delist the Revolutionary Guard as a terrorist organization.

Despite repeated Iranian claims that a separate deal would see billions of dollars in assets unfrozen, the State Department reiterated that no deal is imminent on either a prisoner swap or the nuclear deal.

“Our partners have not released these restricted funds to Iran, nor has the United States authorized or approved any such transfer of restricted funds to Iran,’’ the State Department said late Wednesday.