Iran is under broad UN sanctions for the first time in a decade after failing to strike a new deal on its secretive nuclear programme.
The sanctions, which came into effect overnight, include embargoes, asset freezes and other restrictions that could damage Iran's fragile economy.
Britain, France and Germany initiated a UN procedure to bring back sanctions removed in 2015. They said they had “no choice” but to restore them after Iran flouted limits on its nuclear activities, meant to ensure it never develops an atomic bomb.
But Iran considers these actions “null and void”, Foreign Minister Abbas Araghchi wrote in a letter to UN Secretary General Antonio Guterres. “Iran will not recognise any attempt to extend, revive, or enforce” the sanctions, he said.
Western diplomats said the door to further talks was still open. “Our countries will continue to pursue diplomatic routes and negotiations,” the British, French and German foreign ministers said.
US Secretary of State Marco Rubio urged Tehran to “accept direct talks, held in good faith”. He said other UN members should “pressure Iran's leaders to do what is right for their nation, and best for the safety of the world”.
A last-ditch effort by Russia and China to postpone the sanctions until April failed to win enough votes in the UN Security Council on Friday.
Russia said it would not enforce the sanctions, which should in theory be applied by all UN members. Iran is already under separate sanctions by the US and its allies.
Israel, which bombed Iran's nuclear sites in a brief war in June, considers the restoration of sanctions on Tehran a "major development", its Foreign Ministry said in a post on X on Sunday. "This is a major development in response to Iran’s ongoing violations, especially on its military nuclear programme."
Iran has long insisted it is not seeking nuclear weapons. It recalled its envoys from Britain, France and Germany for consultations on Saturday, state TV reported.
The dollar was trading at about 1.12 million Iranian rials on the black market on Saturday, a record high according to several currency tracking websites. AFP reported brisk business at Tehran jewellery stores as people rushed to buy gold.
The sanctions are a so-called snapback of measures frozen in 2015, when Iran agreed to limits on its nuclear programme under a deal negotiated by former US president Barack Obama.
President Donald Trump quit the deal during his first term, restoring sanctions. Iran has since breached limits on uranium enrichment in what it calls remedial steps.
Conflict over Iran's nuclear activities led to the 12-day air war with Israel in June, which culminated in a US bombing of Iran and an Iranian strike against an airbase in Qatar used by American troops. Iran and the US had held several rounds of Omani-brokered talks before that.
In an address to the UN General Assembly on Friday, Israeli Prime Minister Benjamin Netanyahu urged that there should be no delay in reinstating the sanctions.
He also hinted that Israel was ready to take further military action after the 12 days of bombing that Iranian authorities claimed killed more than 1,000 people.
