Tehran's decision to move the facility comes as diplomatic efforts to restore Iran’s tattered nuclear deal appear stalled.
The visit by International Atomic Energy Agency head Rafael Grossi is seen as critical to clinching a return to the nuclear agreement, and comes parallel to negotiations in the Austrian capital.
According to experts, the strategy of the world powers appears to be "pressuring Iran to bring the talks to a conclusion".
Iranian President Ebrahim Raisi accuses the US of seeking to “weaken independent governments from within” while reminding the world that Tehran is serious about reaching a nuclear deal if the sanctions are lifted.
Iran's head of nuclear energy Mohammad Eslami has said Tehran's targets related to enriching uranium are meeting its industrial and production needs.
The landmark 2015 nuclear agreement, which fell apart in 2018 following US withdrawal, offered a lifting of some of the array of economic sanctions Iran had been under in return for strict curbs on its nuclear programme.
International Atomic Energy Agency chief Rafael Grossi has begun talks with Iranian officials, a week before the resumption of negotiations to salvage the Iran nuclear deal.
UN atomic watchdog's estimate of Iran's stockpile was many times in excess of the limit laid down in the 2015 agreement with world powers.
"We have passed 120 kilogrammes," says Mohammad Eslami, head of the Atomic Energy Organization of Iran.
UN nuclear watchdog says it had received no reply from Tehran over the possible extension of a temporary agreement, covering inspections at Iranian nuclear facilities, which expired on Thursday as nuclear talks crisis looms.
Iran and the European Union move closer to an agreement that would see the US rejoining the nuclear deal it abandoned under the Trump administration.
The IAEA says the results of its inspection work have established "a clear indication that nuclear material and/or equipment contaminated by nuclear material has been present" at three undeclared locations.
Subscribe to our Youtube channel for all latest in-depth, on the ground reporting from around the world.
Copyright © 2022 TRT World.