The Assembly of Experts of Iran has settled on the son of the Ayotollah Ali Khamenei as its next supreme leader, his supporters claim, with the announcement delayed by a dispute over voting procedures.

If it is decided that the assembly does not have to meet in person to vote, its secretariat could simply declare that a consensus had been reached.

“The name of Khamenei will continue,” said Hosseinali Eshkevari, a member of the council tasked with electing a new leader. “The vote has been cast and will be announced soon.”

But Hassan Rouhan, the former president, hinted at delay, saying any announcement should “should come at an appropriate time that doesn’t harm the public focus on the sacred defence”.

The appointment of Mojtaba Khamenei is likely to be rejected by Donald Trump, who has called him “unacceptable”. The US president has insisted on playing a decisive role in the choice while Israel has threatened to kill the next supreme leader and those who selected him.

However, there are forces in Iran who say handing power in wartime to a relative novice would be disruptive. They believe defence efforts should be left in the hands of the armed forces and Ali Larijani, the highly experienced secretary of the supreme national security council. Khamenei, who was deputy chief of staff for his assassinated father, is intimate with the inner workings of the supreme leader’s office, and is being presented as a rejuvenated version of him.

Iran is being run by a temporary tripartite leadership council including the president, Masoud Pezeshkian. On Saturday, Pezeshkian made a botched effort to reset relations with the Gulf states by apologising to them for Iran’s attacks on their territory. He announced it had been decided the strikes would end if Gulf states did not allow attacks on Iran to be mounted from their countries.

Pezeshkian’s comments followed mediation by Russia and a positive response from at least two Gulf states had been expected. But the immediate internal opposition to his stance and continued attacks on the Gulf states prevented that happening. Trump also went on Truth Social to call Pezeshkian’s move a humiliating surrender – a triumphalist tone that undercut Pezeshkian further.

Iran’s foreign minister, Abbas Araghchi, defended the apology – noting that in Iranian culture saying sorry was “a sign of dignity and strength”.

Pezeshkian’s statement was immediately countermanded by the Iranian army, which regards the US bases in the Gulf as legitimate targets in what they regard as an existential war of self-defence. So far 10,000 civilian buildings have been damaged inside Iran.

The army also resented Pezeshkian’s claim that the Islamic Revolutionary Guards Corps had fired at will.

Larijani clarified Iran’s stance in a TV interview, saying: “We have told our neighbours and we repeat: If a base is to be provided to the Americans from your soil to attack Iran from there, it is our undisputed right to respond to those bases. We have said this clearly and we are not lying.”

He also put pressure on the Gulf states to consider the role of the bases if they believed Israel was the chief source of insecurity in the region and the US was Israel’s chief sponsor.

He said: “It makes no sense for a country to declare its friendship with us, but at the same time its base is in the hands of the enemy to attack Iran. Countries in the region must either prevent the US from using their territory against Iran themselves, or we will.

“America’s prestige in the region has been broken and these countries now understand that America is no longer able to provide their security.”

Military sources said the range of attacks on US assets in the Gulf would be widened in response to the US assault on Iranian oil refineries and fuel depots. Iran responded to the onslaught by reducing the maximum daily consumption of petrol but said supplies were stable. Iranian officials did not deny they were receiving intelligence help from the Russians.

Western diplomats say the have seen no letup in Iran’s ability to mount drone and missile attacks and warned the scale of the military assets being poured into the region did not suggest the US intended to make an early unilateral declaration of victory.

Larijani sounded confident in his TV interview that Iranian society was not turning on the government and said Trump’s plan to divide the country into an ethnic patchwork would be rejected by Iranians, including the Kurds.

Despite the rising anger with Iran for training so much of its fire on the Gulf states, most of Gulf governments do not yet to back a counteroffensive against Iran that would put them on the side of the US and Israel.

Iran has admitted that 60% of its missiles and drones have been directed at Gulf states compared with 40% at Israel. Foreign ministers from the Arab League met to discuss their options on Sunday, with one western diplomat saying: “Their patience is running out. The attractiveness of their economies and reputations for stability are being trashed.”

Oman has been telling its neighbours that Iran’s offer on its nuclear programme was serious in the talks that were cut short by the US-Israeli attack. But any settlement is likely to have to be much broader – and include an Iran-Gulf cooperation council.

The United Arab Emirates government described the Iranian attacks as brutal and unprovoked and claimed more than 1,400 ballistic missiles and drones had been aimed at its infrastructure.

It said: “These attacks constitute a flagrant violation of international law and the UN charter, an infringement of the UAE’s sovereignty and territorial integrity, and a direct threat to its security and stability.”

Some Arab diplomats, for all their reservations about Iran’s role in the region, sense the greater risk is that Israel emerges strengthened from this war. Amr Moussa, the former secretary general of the Arab League, warned: “The ongoing attack on Iran is not just an Israeli adventure into which [Benjamin] Netanyahu succeeded in dragging the United States, but a planned strategic American move, in which Washington employed Israel as a regional partner, in a major step toward changing the Middle East, including the Arab world, into a regional geopolitical situation that Israel is trying to lead.”