The global nuclear watchdog has found Iran has failed to meet its non-proliferation obligations for the first time in 20 years.
A resolution passed by the board of governors of the International Atomic Energy Agency (IAEA) carries the threat of an eventual referral to the UN Security Council.
It follows a report from the IAEA last week, which cited a general lack of “co-operation” from Iran and raised concerns over secret activities and undeclared nuclear material in areas which have long been under investigation.
Iran’s foreign minister had warned European powers earlier this week that backing the motion would be a mistake and that it would react strongly.
The move could further complicate talks between Iran and the US over a new nuclear agreement.
It could also escalate tensions in the Middle East, a day after the US advised some Americans to leave the region after reports that the Israeli military was ready to launch strikes on Iranian nuclear sites.
Iran insists its nuclear activities are entirely peaceful and that it would never seek to develop or acquire nuclear weapons.
Under a landmark 2015 deal with six world powers, Iran agreed to limit its nuclear activities and give the IAEA greater access in return for relief from crippling international sanctions.
However, US President Donald Trump abandoned the agreement during his first term in 2018, saying it did too little to stop a pathway to a bomb, and reinstated US sanctions.
Iran has increasingly breached restrictions of the existing nuclear deal in retaliation for the sanctions, particularly those relating to production of enriched uranium, which can be used to make reactor fuel but also nuclear weapons.
The latest IAEA report said Iran had stockpiled more than 408kg (900lb) of uranium enriched to 60% purity, near weapons grade, which would be enough to make nine nuclear bombs.
