Iran has confirmed the transfer of a centrifuge-making facility to its underground nuclear site in Natanz, state media reported, days after the International Atomic Energy Agency announced the installation of cameras to monitor the new plant at Tehran's request.

The report, carried out by the official Iranian news agency IRNA on Saturday evening, comes as diplomatic efforts to restore the nuclear agreement with Iran seem to be stuck.

The news agency quoted a spokesman for the Atomic Energy Organization of Iran, Behrouz Kamalvandi, saying that the authorities had moved the operation to a safer place.

And the Iranian centrifuge manufacturing facility in Karaj was targeted in what Iran described as a sabotage attack last June.

Natanz itself has twice been targeted with sabotage attacks amid uncertainty over the nuclear deal, attacks that Iran has blamed on Israel.

"Unfortunately, due to the terrorist operation that took place in Karaj, we had to intensify security measures, according to which we transferred an important part of the machinery to Natanz and Isfahan," which host two nuclear facilities, Kamalvandi said.

On Thursday, the International Atomic Energy Agency said it had installed cameras and removed seals from machinery at the new workshop in Natanz two days earlier.

These machines will be used to make rotating tubes and centrifugal bellows, which are important parts of devices that rotate at very high speeds to enrich uranium gas.

Kamalvandi reiterated Iran's position that Tehran would not provide data from the cameras to the IAEA if it did not reach an agreement.

Talks between Iran and world powers in Vienna to revive the 2015 nuclear deal have stalled. There are fears that Iran is close to building a nuclear weapon if it chooses to pursue this path.

The nuclear deal collapsed four years ago as the United States withdrew from it and re-imposed sanctions on Iran. At the same time, Iran has significantly expanded the scope of its nuclear work.