"What we have been informed is that 27 cameras... are being removed in Iran," he told reporters.

"So this of course poses a serious challenge to our ability to continue working there."

Grossi said if a solution was not found within three to four weeks to this issue, this would be "a fatal blow".

Iran announced this week it was disconnecting some IAEA cameras monitoring its nuclear sites in anticipation of the watchdog's adoption of the Western-drafted censure motion on Wednesday.

Tehran on Thursday condemned the motion as "unconstructive" in a new spat that clouds efforts to revive a deal limiting its nuclear activities.

Grossi said about 40 cameras remained in the Islamic republic.

"I invite Iran to engage with me immediately... We are in a very tense situation," Grossi said.

"Does this mean it's the end of the line? I think this shouldn't be the case. Not yet... Let's hope that emotions go down a little bit."

The motion submitted by the United States, Britain, France and Germany was the first to criticise Iran since June 2020.

The motion was approved by 30 of the 35 members of the IAEA board of governors, with only Russia and China voting against it.