The UN atomic energy watchdog said on Thursday that Iran was removing 27 surveillance cameras at its nuclear facilities, warning this could be a “fatal blow” to negotiations to revive a landmark deal. Talks began in April last year to bring the United States back to the 2015 accord, lifting sanctions, and Iran back into compliance, limiting its nuclear activities. But negotiations have stalled since March, and raising tensions, International Atomic Energy Agency (IAEA) members on Wednesday passed a resolution censuring Iran over its lack of cooperation with the watchdog. Iran has condemned the motion as “unconstructive”, announcing earlier on Wednesday that it had disconnected some IAEA cameras monitoring its nuclear sites. “What we have been informed is that 27 cameras … are being removed in Iran,” IAEA chief Rafael Grossi told reporters on Thursday. “So this of course poses a serious challenge to our ability to continue working there.” Grossi urged Iran to engage with him “immediately”. He said if a solution was not found within three to four weeks to the issue, this would be “a fatal blow” to negotiations. Grossi said about 40 monitoring cameras remained in the Islamic republic.