The motion drafted by the United States, Britain, France and Germany was carried by 19 votes in favour in the 35-member governing board, three diplomatic sources told AFP.

It is the latest diplomatic manoeuvre in a years-long effort to restrict Iran's nuclear activities over Western fears that it is seeking to develop nuclear weapons, which it denies.

China, Russia and Burkina Faso voted against the text, while 11 countries abstained, diplomats told AFP.

Paraguay and Venezuela were unable to participate due to insufficient financial contributions.

Ahead of the vote, Tehran had threatened to "react very strongly" by reducing its cooperation with the International Atomic Energy Agency (IAEA) in case the resolution was adopted.

Diplomats said the resolution is designed to up pressure on Tehran.

The censure comes as the United States and Iran held several rounds of talks mediated by Oman to secure agreement on limiting Iran's nuclear programme in exchange for sanctions relief.

But tensions have been mounting in the Middle East and US President Donald Trump has said he was "less confident" about reaching a nuclear agreement.

On Wednesday, Iran threatened to target US military bases in the region if conflict breaks out.

Another round of nuclear talks are scheduled to take place in Muscat on Sunday.

"The United States is negotiating in good faith to reach a deal that allows us to say with confidence what President Trump has said time and again: Iran will never acquire a nuclear weapon," US charge d'affaires Howard Solomon said in a statement during this week's IAEA board meeting.

"Iran now has a clear opportunity to build confidence: by providing the Agency with greater transparency" and "ceasing its escalatory nuclear activities", he said.

The resolution adopted Thursday calls on Iran "to urgently remedy its non-compliance" with its commitments under the Non-Proliferation Treaty (NPT).

It also "deeply regrets" that Tehran "despite repeated calls from the Board and many opportunities offered... has failed to cooperate fully with the Agency".

IAEA's "inability... to provide assurance that Iran's nuclear programme is exclusively peaceful gives rise to questions that are within the competence of the United Nations Security Council (UNSC)", which can draw up sanctions, the resolution said.

For years, the IAEA has been trying to obtain clarification on nuclear material and equipment found at undeclared sites and resulting from undeclared activities carried out until the early 2000s.

Tehran has also accelerated production of near-weapons-grade uranium in recent months.

Iran has gradually broken away from its commitments under the nuclear deal it struck with world powers in 2015.

The landmark deal provided Iran sanctions relief in exchange for curbs on its atomic programme, but it fell apart after the unilateral withdrawal of the United States in 2018.

Efforts to revive the deal have so far failed.