Iran snubs UN nuclear energy conference in Abu Dhabi
Iran officials left their seats empty as the head of the International Atomic Energy Agency avoided speaking about the nuclear deal at all in his address at the venue.
Iranian officials did not respond to a request for comment to discuss their decision to avoid the conference.
Yukiya Amano's decision may have been tactical after visiting Tehran just the day before and telling journalists that Iran still honoured the accord.
Both the UAE and neighbouring Saudi Arabia remain highly suspicious of the nuclear deal, which saw economic sanctions on Iran lifted in exchange for it limiting its enrichment of uranium.
The two Gulf Arab countries say that new money flowing into Iran has aided its ability to back Shia militias in Iraq and support embattled Syrian President Bashar al-Assad.
Also sharing that suspicion is Israel, which sent a delegation to the nuclear conference. The UAE, like many Arab nations does not have official diplomatic ties with Israel, although there has speculation over secret relations.
In June, leaked emails of the UAE's ambassador to the US revealed that Abu Dhabi had established clandestine relations with Israel.
The emails showed a "growing link" between the UAE and pro-Israel think-tank, Foundation for Defence of Democracies.
Israeli officials have been repeatedly suggesting there is a profound cooperation with UAE and Saudi Arabia.
Conference organisers asked journalists not to film the Israeli delegation.
Israeli officials did not immediately return a request for comment. Their presence also nearly created a unique diplomatic conundrum, as conference organisers had seated them next to arch rivals Iran.
The Iran nuclear deal, struck in 2015, now faces one of its biggest threats. President Donald Trump has declined to re-certify the deal, sending it to Congress to address, sparking a new war of words between Iran and the United States, fueling growing mistrust and a sense of nationalism among Iranians.
The European Union, Britain and other parties in the deal have all encouraged Trump to keep the accord in place.