Guterres said building trust through dialogue is essential, speaking in response to a question from Iran International's reporter at the UN on Tuesday.
“My appeal to Iran and to the other powers is to use diplomacy and to create the conditions of trust in order to be able to avoid it,” UN Secretary General said.
Guterres added that he has been in contact with both sides and aimed to facilitate discussions.
“Of course, offering my good offices, but it all depends on the diplomatic efforts that are made in order to establish the trust that is needed for the snapback to be avoided,” Guterres said.
Last month, France, Germany, and the United Kingdom triggered the UN snapback sanctions mechanism in a partly lapsed 2015 international nuclear deal with Iran.
The move initiated a 30-day window for diplomacy before sanctions are due to take effect on October 18.
Iran-IAEA cooperation
One of the demands of the three European countries is the immediate resumption of full work between Iran and the International Atomic Energy Agency (IAEA), the UN nuclear watchdog.
Iran and the IAEA signed an agreement in Cairo last week aimed at eventually resuming nuclear inspections in Iran. IAEA chief Rafael Grossi on Monday urged Iran to immediately implement the deal to resume inspections.
Iran's nuclear chief Mohammad Eslami on Tuesday criticized European powers for adopting an even more bellicose rhetoric against Tehran after the Cairo deal.
"From the very moment the agreement was signed between our esteemed foreign minister and the IAEA director general, we witnessed new and harsher positions from European countries," he told reporters in Vienna.
The Europeans also seek unconditional renewed talks with the United States severed since Israeli and US attacks on Iran in June.
Last month, Iran’s Supreme Leader Ali Khamenei rejected calls by Tehran moderates for direct negotiations with the United States, insisting that Washington’s hostility cannot be resolved through talks.