Rafael Grossi's trip comes ahead of Tuesday date set by Iranian lawmakers to limit cooperation with IAEA unless US sanctions are lifted

Iran plans to restrict UN inspections if the US does not lift sanctions by February 21; Thursday meeting 'unlikely' to prevent Tehran from moving ahead

IAEA head to visit Tehran, ahead of Iranian intention to end snap inspections

Nuclear watchdog head Grossi says if talks are held when Biden takes office, ‘there will have to be clear understanding on how initial terms of accord will be recomplied with’

UN atomic watchdog head says additional understandings must lay out how Iran's violations of multilateral accord can be reversed, as parties are no longer at 'square one'

IAEA says centrifuge structure meant to replace Natanz plant hit by mysterious explosion over summer; Tehran had promised to replace site with more secure one in mountains

Rafael Grossi, head of International Atomic Energy Agency, says Tehran's granting inspectors access to two disputed sites could build cooperation

UN inspectors gain access to one of two sites where undeclared nuclear activity may have taken place in the early 2000s; second site to be inspected later this month

Signatories to the agreement will hold talks as Tehran continues to ramp up nuclear activities

Amid tensions with US, Tehran 'voluntarily providing the IAEA with access' to locations in central Iran and close to capital