Donald Trump said on Sunday he was prepared to talk to what was left of the Iranian leadership in the wake of the killing of the country’s supreme leader by US-Israeli air strikes aimed at overthrowing the regime.

Trump was speaking as a second day of intense bombing of Iranian cities and Tehran’s missile counter-attacks sent tremors across the region and through the global economy.

Oil prices jumped 10% to $80 a barrel for Brent crude, amid predictions that the continuing war could soon drive it to $100, after attacks on two ships largely choked off tanker traffic through the strait of Hormuz out of the Gulf.

Amir-Saeid Iravani, the Iranian ambassador to the UN, told an emergency security council meeting on Saturday that hundreds of civilians had been killed or injured in the US-Israeli strikes. He said they had deliberately targeted civilian neighbourhoods in multiple cities.

The death toll is expected to climb after a second day of bombing. Iranian state media said that 165 people had been confirmed dead in a bomb attack on a girls’ primary school in the southern city of Minab on Saturday.

Among the dead was the country’s supreme leader, Ali Khamenei, who had ruled since 1989 and was the primary target of an initial Israeli strike on Saturday morning. According to several US reports, the CIA had been tracking Khamenei for months. The New York Times reported the CIA tipped off Israel when the leader convened a meeting of top defence aides at his compound in Tehran, triggering a decision to strike.

Israel’s Channel 12 reported that the Israeli army employed a ruse to put the Iranian leadership off its guard. On the morning of the operation, army officers were asked not to park their cars in their usual spaces to avoid detection by Iran’s spies. Misinformation was also leaked suggesting that the chief of staff Lt Gen Eyal Zamir had stayed at home.

The channel cited officials as saying the Israeli air force killed 30 high-ranking Iranian officials within the first 30 seconds of the attack.

Trump told Fox News that 48 Iranian leaders had been killed in the first two days of bombing, and claimed in a social media post that nine Iranian warships had been sunk and the naval headquarters destroyed.

Nine Israelis have so far died in Iranian missile counter-strikes, and US forces confirmed their first casualties of the war: three dead and five injured by shrapnel. The official announcement did not give details on where and how the casualties occurred.

Iran has also targeted Gulf countries that host US military bases. Airports in Kuwait, Abu Dhabi and Dubai were damaged by missiles and remained shut on Sunday, causing one of global aviation’s most severe disruptions in years.

Benjamin Netanyahu meanwhile vowed to intensify the aerial attacks on Iran.

The Israeli prime minister said: “Our forces are now striking at the heart of Tehran with intense power, and this will only escalate in the days ahead.”

Trump claimed the assault on Iran, launched with the stated aim of regime change, was “moving along rapidly”.

In a separate interview, Trump said he was open to talks with Iran’s surviving and newly appointed leaders.

“They want to talk, and I have agreed to talk, so I will be talking to them,” he told the Atlantic magazine, without revealing when those talks might start. “They should have done it sooner. They should have given what was very practical and easy to do sooner. They waited too long.”

Asked whether he was ready to prolong the war in support of an Iranian popular uprising against the regime, Trump was non-committal, saying only he would “look at the situation at the time it happens”.

He was speaking as the global effects of the war began to be felt. The oil price spike followed two reported attacks on tankers in or near the strait of Hormuz.

Iranian state television said an oil tanker was struck and was sinking after trying to “illegally” pass through the strait, which Iran’s Islamic Revolutionary Guards has declared closed.

Some 150 tankers were reported to have dropped anchor rather than transit the waterway, a route for about a fifth of the world’s traded oil. Major container shipping companies, including MSC and Maersk, have suspended navigation in the region.

The ship attacks were a reminder of the conflict’s potential to trigger an environmental catastrophe.

In launching the war, Trump said it would provide an opportunity for the Iranian people to rise up and overthrow the 47-year-old Islamic regime. Nationwide protests earlier this year were brutally suppressed by security forces, and some estimates say tens of thousands of civilians were killed.

Iranian authorities said that 22 border guards at Mehran on the Iranian-Iraqi border had been killed, in a sign that the US and Israel were seeking to weaken the regime’s control of Iran’s borders in support of anti-government separatists.

Across the country, Iranians said they felt a mixture of terror and optimism as the bombings continued. Some expressed relief that the long-expected strikes had arrived and opponents of the regime spoke of hope that they might lead to political change – but both were tempered by fear that the attacks would bring more civilian deaths to a country already reeling from recent bloodshed.

Iran’s top security official, Ali Larijani, accused the US and Israel of trying to plunder and fragment Iran and warned “secessionist groups” of a harsh response if they attempted to intervene, state television said.

The regime in Tehran insisted that Khamenei’s killing would not weaken its resolve. Iran’s parliament speaker, Mohammad Bagher Ghalibaf, said Netanyahu and Trump had “crossed a red line” and “will pay for it”, according to state media.

President Masoud Pezeshkian said a leadership council composed of himself, the judiciary head and a member of the powerful Guardian Council had temporarily assumed the duties of supreme leader until a replacement was chosen. Khamenei had not designated a successor.

Esmaeil Baghaei, a spokesperson for Iran’s foreign ministry, said he expected the process of selecting a new supreme leader to be relatively quick.

“Of course, there is no fixed timeline,” Baghaei told the MS Now Velshi programme. “They can decide as quickly as possible. I don’t think it would take that long because we are under this critical situation of an imposed war of aggression by the United States and Israel. So I guess the process would be expedited.”

In his interview with the Atlantic, Trump shrugged off the suggestion that the economic fallout from the war could damage the Republican party’s prospects in November’s congressional elections.

“We have the greatest economy we’ve ever had,” the president claimed. However, according to a Reuters-Ipsos poll on Sunday, only about one in four Americans approve of the attack on Iran, before any inflationary pressure from a war-driven oil price spike has begun to be felt in the US.