Saudi Arabia's foreign minister said on Sunday that Iran's Gulf neighbours would act to shore up their security if Tehran were to obtain nuclear weapons.
Indirect US-Iranian talks to salvage a 2015 nuclear pact between global powers and Iran, which Washington exited in 2018, stalled in September.
The UN nuclear chief has voiced concern over a recent announcement by Tehran that it was boosting enrichment capacity.
"If Iran gets an operational nuclear weapon, all bets are off," Prince Faisal bin Farhan Al Saud said in an on-stage interview at the World Policy Conference in Abu Dhabi
"We are in a very dangerous space in the region...you can expect that regional states will certainly look towards how they can ensure their own security."
"We hear from the Iranians that they have no interest in a nuclear weapons programme; it would be very comforting to be able to believe that. We need more assurance on that level."