Iran rejected a 45-day ceasefire proposal and said it wants a permanent end to the war, while US President Donald Trump appeared to widen his threat from civilian targets to the whole Islamic Republic as his ultimatum ticked closer.
“The entire country can be taken out in one night, and that night might be tomorrow night,” Mr Trump told a news conference on Monday at the White House.
He has called his Tuesday 8pm deadline for Iran to make a deal final.
The US stepped up threats against Iran to open the Strait of Hormuz or face a barrage of attacks on civilian targets.
“Today will be the largest volume of strikes since day one,” US defence secretary Pete Hegseth said.
“Tomorrow, even more than today.”
US President Donald Trump speaks with reporters in the James Brady Press Briefing Room at the White House (Mark Schiefelbein/AP)
Asked about accusations of war crimes if the US widens attacks against Iran’s bridges and power plants, Mr Trump responded: “No, not at all.”
Asked why Iranians would want him to carry out the threat, he said citizens are “willing to suffer…in order to have freedom”.
But there has been no sign of an uprising in Iran as residents shelter from bombardment.
Students inspect damage at a mosque at Tehran’s Sharif University of Technology complex that Iranian authorities say was hit by a US-Israeli strike (Francisco Seco/AP)
International warnings piled up against expanded strikes.
“Any attack on civilian infrastructure is a violation of international law and a very clear one,” United Nations spokesman Stephane Dujarric later told journalists.
Israel piled on pressure by attacking a major gas field that is Iran’s biggest source of domestic energy.
Tehran conveyed its 10-point response through Pakistan, a key mediator, including proposals on reconstruction and the lifting of sanctions, Iran’s state-run IRNA news agency said.
Demonstrators attend a pro-government gathering in a square in Tehran (Francisco Seco/AP)
“We only accept an end of the war with guarantees that we won’t be attacked again,” Mojtaba Ferdousi Pour, head of Iran’s diplomatic mission in Cairo, told The Associated Press.
He said Iran no longer trusts the Trump administration after the US bombed the Islamic Republic twice during previous rounds of talks.
And yet a regional official involved in talks said efforts had not collapsed.
“We are still talking to both sides,” he said, speaking on condition of anonymity to discuss closed-door diplomacy.
Iranian and Omani officials were working on a mechanism for administrating the strait, through which a fifth of the world’s oil is shipped in peacetime.
(PA Graphics)
Iran’s grip on it has shaken the world economy and Tehran has refused to let US and Israeli vessels through after they started the war on February 28.
Israel struck a key petrochemical plant in the South Pars natural gas field and killed two paramilitary Revolutionary Guard commanders, including its intelligence chief.
The gas field attack aimed at eliminating a major source of revenue for Iran, Israel said.
The field, the world’s largest, is shared with Qatar and is critical to electricity production for Iran’s 93 million population, but the strike appeared to be separate from Mr Trump’s threats.
An earlier Israeli attack on the field in March prompted Iran to target energy infrastructure in other Middle Eastern countries, a major escalation.
Mr Trump has warned Iran that the US could set the country “back to the stone ages”, including targeting power plants and bridges.
A woman holds an Iranian flag at an intersection in central Tehran (Francisco Seco/AP)
Earlier on Monday, Trump addressed an Easter event on the White House lawn and suggested that future attacks could go further.
“If I had my choice, what would I like to do? Take the oil,” he said, suggesting it could be done easily, but “unfortunately the American people would like to see us come home”.
Asked if Tuesday at 8pm Washington time was his final deadline, Mr Trump replied simply: “Yeah.”
Egyptian, Pakistani and Turkish mediators had sent Iranian foreign minister Abbas Araghchi and US Middle East envoy Steve Witkoff a proposal calling for a 45-day ceasefire and the reopening of the strait, two Middle East officials told The Associated Press.
The officials spoke on condition of anonymity to discuss the private negotiations.
Iran’s foreign ministry spokesman Esmail Baghaei earlier told journalists that messages were being exchanged with mediators but “negotiations are entirely incompatible with ultimatums, crimes and threats of war crimes”.
Nadine Naameh reacts as she looks at the damage to her home following an Israeli strike in the village of Ain Saadeh in the mountains east of Beirut, Lebanon (Emilio Morenatti/AP)
In Islamabad, two senior officials said Pakistan’s ceasefire efforts are at an advanced stage but “several spoilers and detractors” are trying to sow confusion.
The officials spoke on condition of anonymity because they were not authorised to speak publicly about the talks.
Meanwhile, explosions boomed in Tehran and low-flying jets could be heard for hours.
Among those killed was the head of intelligence for Iran’s paramilitary Revolutionary Guard, Major General Majid Khademi, according to Iranian state media and Israel’s defence minister.
Israel said it also killed the leader of the Revolutionary Guard’s undercover unit in its expeditionary Quds Force, Asghar Bakeri.
Israel’s defence minister vowed to keep targeting top-ranking officials.
A man sits beside an Iranian flag banner during a protest by medical workers against the US-Israeli military campaign outside Imam Khomeini Hospital in Tehran (Francisco Seco/AP)
“We will continue to hunt them down one by one,” Israel Katz said.
Israel’s military later said it struck three Tehran airports overnight — Bahram, Mehrabad and Azmayesh — hitting dozens of helicopters and aircraft it said belonged to the Iranian Air Force.
A Tehran resident said “constantly there is the sound of bombs, air defences, drones”, speaking on condition of anonymity for her safety.
At least one recent attack hit near her home, waking her, she said.
Separately, Kuwait, the UAE and Saudi Arabia activated air defences to intercept Iranian missiles and drones.
Tehran has kept up pressure on Gulf neighbours, which has included strikes against infrastructure like oil fields.
A man works at the site of Sunday’s Israeli strike on a building in Beirut’s Jnah neighbourhood, Lebanon (Emilio Morenatti/AP)
In Israel, Iranian missiles hit the northern city of Haifa, where four people from one family were found dead in the rubble of a residential building.
Iran’s attacks on regional energy infrastructure and its hold on the Strait of Hormuz have sent global energy prices soaring.
Brent crude oil, the international standard, rose to 109 dollars (£82) in early Monday spot trading, about 50% higher than when the war started, then wavered. US stocks were mostly holding steady.
Former Iranian foreign minister Ali Akbar Velayatir urged Arab countries to discourage Mr Trump from striking power plants, warning on social media that the entire region would go “dark” if that happens.
Iran has let some vessels through the strait since the war began with US and Israeli attacks on February 28, but none belong to those countries or ones perceived as helping them.
Some have paid Iran for passage but the flow of traffic is down more than 90% over the same period last year.
A tourist ferry sails past the Indian flagged LPG carrier Jag Vasant at the Mumbai Port, India, after it arrived clearing the Strait of Hormuz (Rafiq Maqbool/AP)
Thick smoke rose near Tehran’s Azadi Square after an airstrike hit the grounds of the Sharif University of Technology.
Multiple countries have sanctioned the university for its work with the military, particularly on Iran’s ballistic missile programme.
Mr Araghchi called university “the MIT of Iran”, posting on social media that “Aggressors will see our might”.
Iranian media reported damage to buildings and a natural gas distribution site next to campus.
The university is empty as the war has forced all schools into online classes.
A strike near Eslamshar, south-west of Tehran, killed at least 15 people, authorities said.
Workers remove debris at Tehran’s Sharif University of Technology complex that Iranian authorities say was hit by a US-Israeli strike (Francisco Seco/AP)
Five were killed in a residential area in Qom, and six were killed in strikes on other cities, the state-run Iran daily newspaper reported.
Three people were killed at a home in Tehran, state television reported.
In Lebanon, where Israel has launched air attacks and a ground invasion that it says target the Iran-linked Hezbollah militia, an airstrike hit an apartment in Ain Saadeh, a predominately Christian town east of Beirut.
It killed an official in the Lebanese Forces, a Christian political party strongly opposed to Hezbollah, his wife and another woman.
“We had always felt safe here,” family friend Nadine Naameh said.
A shopkeeper sells spices at Tajrish Bazaar in Tehran (Francisco Seco/AP)
More than 1,900 people have been killed in Iran since the war began, but the government has not updated the toll for days.
More than 1,400 people have been killed in Lebanon and more than one million people have been displaced.
Eleven Israeli soldiers have died there.
In Gulf Arab states and the occupied West Bank, more than two dozen people have died, while 23 have been reported dead in Israel and 13 US service members have been killed.