Donald Trump vetoed a plot by Israel to assassinate Ayatollah Ali Khamenei amid an escalation in the country's military activity with Iran, reports suggest.
The US president opposed an operation by the Israel Defence Forces to kill Iran’s supreme leader, two officials told Reuters.
But Mr Trump said was possible that his military “could get involved” in the conflict between Israel and Iran, telling ABC America was “not at this moment involved”.
His comments came after Iran fired a new wave of missiles at Israel in Tehran’s first daytime strike since the row exploded three days ago.
Iranian media said 50 missiles were launched at Israel on Sunday in the latest burst of violence between the Middle East foes.
It has raised fears of an all-out regional war that could even suck in the US, the UK and other Western allies.
There have been conflicting accounts about whether Mr Trump allowed Israel to strike Iran on Friday.
Asked about reports Mr Trump rejected the plot to kill the Ayatollah, Israeli prime minister Benjamin Netanyahu told Fox News: “There are so many false reports about conversations that never happened — I’m not going to get into it.”
Meanwhile, the United Kingdom is advising Britons against all travel to Israel.
On Sunday, the government updated its travel guidance for Israel from “amber” to “red” — on the same level as Iran.
The warning was ramped up two days the UK advised against all but “essential” travel to Israel, following Israel’s sudden military attack on Iran that targeted the Middle East rival’s nuclear sites and top commanders.
On Sunday, explosions boomed across Tehran as Israel launched an expanded assault on Iran.
“Tehran is burning,” Israeli defence minister Israel Katz said on X, formerly known as Twitter.
Casualty figures were not immediately available in Iran, where Israel targeted its Defence Ministry headquarters in Tehran, as well as sites that it alleged were associated with the country’s nuclear programme.
The Islamic Revolutionary Guard Corps claimed Iranian missiles targeted fuel production facilities for Israeli fighter jets, something not acknowledged by Israel.
Mohammad Kazemi, the head of the Intelligence Organisation of the IRGC, was also killed.
Five car bombs detonated in Tehran, according to Iran’s IRNA news agency, although Israel denied any involvement.
Iranian missiles entered Israel’s skies in simultaneous attacks which claimed at least 10 lives, according to officials.
Israel's ambulance service said those killed included a 10-year-old boy, a young girl and a woman in her 20s, while more than 140 were injured.
Israeli rescue teams combed through the rubble of residential buildings destroyed in strikes, using flashlights and sniffer dogs to look for survivors.
At least 35 people were reported to be missing after a strike hit Bat Yam, a coastal suburb of Tel Aviv. Iran's state TV said the country attacked Haifa and other cities "with tens of Iranian missiles and drones".
Amid the continued conflict, planned negotiations between Iran and the United States over Tehran’s nuclear program were cancelled, throwing into question when and how an end to the fighting could come.
Both Israel’s military and Iran’s state television announced the latest round of Iranian missiles as explosions were heard near midnight, while the Israeli security cabinet met.
Israel’s ongoing strikes across Iran have left the country’s surviving leadership with the difficult decision of whether to plunge deeper into conflict with Israel’s more powerful forces or seek a diplomatic route.
World leaders made urgent calls to deescalate and avoid all-out war. The attack on nuclear sites set a “dangerous precedent,” China’s foreign minister said.
The UK is sending more RAF jets to the Middle East after Iran threatened to target UK, French and US bases if the countries help stop strikes on Israel.
Speaking to reporters travelling with him on a visit to Canada, Prime Minister Sir Keir Starmer declined to rule out intervening in the conflict entirely but made clear he would continue pressing for de-escalation and said the “intense” developments over the weekend would be discussed in detail at the G7 summit.
Mr Trump said the US had “nothing to do with the attack on Iran” and warned Tehran against targeting US interests in retaliation.
“If we are attacked in any way, shape or form by Iran, the full strength and might of the US Armed Forces will come down on you at levels never seen before. However, we can easily get a deal done between Iran and Israel, and end this bloody conflict!!!” Mr Trump wrote on Truth Social platform on Saturday.
The region is already on edge as Israel makes a new push to eliminate the Iranian-backed militant group Hamas in Gaza after 20 months of fighting.
Israel — widely believed to be the only nuclear-armed state in the Middle East — said its hundreds of strikes on Iran over the past two days have killed a number of top generals, nine senior scientists and experts involved in Iran’s nuclear programme.
Israel’s strikes on Iran have killed at least 400 people and wounded another 650, according to Human Rights Activists, a group based in Washington .
The sixth round of US-Iran indirect talks on Sunday over Iran’s nuclear programme will not take place, mediator Oman said.
“We remain committed to talks and hope the Iranians will come to the table soon,” said a senior US official, speaking on condition of anonymity to discuss diplomacy.
Iran launched its first waves of missiles at Israel late Friday and early on Saturday.
The attacks killed at least three people and wounded 174, two of them seriously, Israel said. The military said seven soldiers were lightly wounded when a missile hit central Israel, without specifying where.
US ground-based air defence systems in the region were helping to shoot down Iranian missiles, said an official who spoke on condition of anonymity to discuss the measures.
Israel’s main international airport said it will remain closed until further notice.
First responders were looking for survivors and clearing the remnants of a missile that fell on a neighbourhood outside of Tel Aviv early on Sunday morning.
Responders used a drone at points to look for survivors in some of the areas that were too hard to access.
Some people were fleeing the area with their belongings in suitcases.
