Iran says no talks after US sanctions Ayatollah Ali Khamenei

US sanctions on Iran’s supreme leader Ayatollah Ali Khamenei imposed four days after an American military drone was shot down in Gulf waters reduced the chances of talks that could lead them away from conflict.

As world powers called for diplomacy and de-escalation, the situation worsened after President Donald Trump formally announced economic measures against Iran’s head of state and eight commanders of its Islamic Revolutionary Guard Corps.

The new sanctions, 24 hours after Mr Trump said he was willing to talk to Iran without conditions, and the threat of more to come mean there can be no direct talks, Tehran’s permanent representative to the UN said.

Majid Takht-Ravanchi said the steps taken against Mr Khamenei’s office, after America’s decision to send more forces to the Gulf, were “yet another indication of continued US hostility against Iran’s people and its leaders”.

Mr Takht-Ravanchi called on the UN to take charge of negotiations over the crisis.

On Tuesday, Iran's Foreign Ministry spokesman Abbas Mousavi said the sanctions meant the "permanent closure of the road of diplomacy" with the United States.

Iran was locked out of a Security Council meeting about attacks on oil tankers in the Gulf of Oman two weeks ago, which Washington has blamed on Tehran, and the shooting down of a drone by the Revolutionary Guards in the early hours of Thursday.

After a briefing from the US, the council repeated its condemnation of the tanker attacks in the Gulf and the earlier sabotage of four vessels off Fujairah, but did not identify Iran as the perpetrator.

Instead, it called the incidents “a serious threat to maritime navigation and energy supply”.

“Differences must be addressed peacefully and through dialogue,” said Kuwait’s ambassador to the UN, Mansour Al Otaibi, the current chairman of the council.

But the acting US representative to the UN, Jonathan Cohen, later said that Iran was behind the tanker attacks and that last week’s shooting down of the drone was unprovoked.

“The only state actor with the capabilities and the motive to carry out these attacks is Iran,” he said of the tanker attacks. “There is no other credible explanation.

“US information confirms Iranian vessels approached the two vessels before the explosions took place and then monitored the vessels as the explosions happened.”

France, Germany and Britain said they were gravely concerned by increased tension in the Gulf, including Iran shooting down the drone.

“These developments risk miscalculation and conflict,” said Christoph Heusgen, Germany’s ambassador to the UN. “We call for de-escalation and dialogue with full respect for international rules.”

Monday’s sanctions were the latest step in Washington’s “maximum pressure” campaign against Iran after the Trump administration’s withdrawal from the 2015 nuclear deal.

Russia’s ambassador to the UN, Vassily Nebenzia, said the US had made matters worse.

“Let’s remember who started all this,” Mr Nebenzia said. “What kind of dialogue can you have with a knife at your throat?”

Richard Nephew, a former US State Department official and sanctions expert, said the window for diplomacy was closing.

“The way out of this is that both sides decide that leverage building has less value than avoiding conflict, and start to talk,” Mr Nephew said.

“The problem is that both are creating their own credibility traps and saying ‘We can’t negotiate with them because then we’ll look weak’. That is totally toxic.”

Mr Trump has repeatedly said that the nuclear agreement failed to curb Tehran’s “destabilising activities” in the Middle East, including its ballistic missile programme, or place permanent restraints on its atomic programme.

He has also warned that foreign companies will face sanctions if they conduct business with Iran, urging other parties to the agreement to follow the US withdrawal.

But Britain, China, France, Germany and Russia have vowed to stick by it. Mr Heusgen said on Monday that Europe was still committed to the deal because it “contributes to reducing tensions in the region as well as global nuclear proliferation”.

Before the council meeting, Mr Takht-Ravanchi repeated Iranian Foreign Minister Javad Zarif’s assertion that the US drone was in Iranian airspace and was warned that action was imminent.

Mr Trump ordered retaliatory strikes but later backed down, reportedly 10 minutes before they were to be launched, instead opting for a cyberattack and further economic sanctions.

Iran has written to UN Secretary General Antonio Guterres to urge the world body to lead in finding a way to avoid war, Mr Takht-Ravanchi said.

He said face-to-face talks with the US were not possible in the current circumstances.

“The mandate is there,” Mr Takht-Ravanchi said. “On dialogue with the US, dialogue has certain rules and regulations.

“You cannot start a dialogue with someone who is threatening you, who is intimidating you. Today we have just witnessed the United States imposing another set of sanctions on Iran.

“How can we start a dialogue with somebody whose primary preoccupation is to put more sanctions on you?”