Tehran residents said they were deeply worried about the return of United Nations sanctions and a nosediving local currency.

The sanctions, suspended under an agreement with world powers in 2015, are set to be reimposed early Sunday, pending a last minute diplomatic breakthrough.

Residents on Saturday said they feared sanctions would deteriorate the already ailing economy, which has been hard hit by U.S sanctions and "maximum pressure" campaign.

Britain, Germany and France have activated the so-called "snapback" mechanism, after talks with Iran over its nuclear and missile programs failed to result in an agreement.

U.N inspectors have not been allowed to visit Iran's nuclear sites attacked by Israel and the United States in June, and the fate of Iran's enriched uranium stockpile remains unclear.

Iranian officials have been trying to downplay the possible impact of the development, saying the U.S sanctions already in place are much tougher than the sanctions being restored.