United States President Donald Trump has announced a "complete and total" ceasefire between Israel and Iran will go into force with a view to ending the conflict between the two nations.
Trump appeared to suggest that Israel and Iran would have some time to complete any missions that are underway, at which point the ceasefire would begin in a staged process.
"On the assumption that everything works as it should, which it will, I would like to congratulate both Countries, Israel and Iran, on having the Stamina, Courage, and Intelligence to end, what should be called, 'THE 12 DAY WAR'," he wrote on his Truth Social site.
Trump declared a ceasefire minutes after each side threatened new attacks.
CNN reported shortly before Trump's post that Iran had not received any ceasefire proposal and saw no reason for one, citing a senior Iranian official.
Earlier on Monday, Trump said he would encourage Israel to proceed towards peace after dismissing Iran's attack on an American air base that caused no injuries and thanking Tehran for the early notice of the strikes.
There was no immediate comment from Israel on Trump's statement.
Hours earlier, three Israeli officials had signaled Israel was looking to wrap up its campaign in Iran soon and had passed the message on to the United States.
S&P 500 futures rose 0.4% late on Monday, suggesting traders expect the U.S. stock market to open with gains on Tuesday.
Israel earlier said it carried out its most extensive wave of attacks on Tehran ever on Monday.
Targets included a Tehran prison where Iran's leadership holds political opponents, in a renewed demonstration of its willingness to strike beyond its previously stated military and nuclear targets to target key pillars of Iran's ruling system.
Despite Iran's threats to challenge oil shipments from the Gulf, oil prices fell 7% in volatile trading, suggesting traders doubted the Islamic Republic would follow through on any action that would disrupt global supplies.
Qatar, situated just across the Gulf from Iran, closed its airspace after receiving the advance warning from Iran, a source familiar with the matter told Reuters.
Iranian Foreign Minister Abbas Araqchi met Russian President Vladimir Putin in Moscow as Tehran sought backing from one of its last major power friends for its next steps.
STRIKING 'REGIME TARGETS'
Israel made clear that its strikes on Evin prison and other targets in Tehran were intended to hit the Iranian ruling apparatus broadly, and its ability to sustain power.
Iran's IRIB state broadcaster released video showing rescue workers combing the flattened wreckage of a building at the prison, carrying a wounded man on a stretcher. The Mizan news outlet of Iran's judiciary said urgent action was being taken to protect the health and safety of inmates there.
Evin has long been Iran's primary prison for political detainees and people accused of espionage, as well as the site of executions that remain strong memories for the opposition. Several high-profile foreign prisoners are also held there.
Israel's military said it had also struck Revolutionary Guard command centres responsible for internal security in the Tehran area.
The military was "currently striking, with unprecedented force, regime targets and governmental repression bodies in the heart of Tehran," Defence Minister Israel Katz said in a statement.
Much of Tehran's population of 10 million has fled after 10 days of bombing. Tasnim News Agency reported a strike at an electricity feeder station in the Evin neighbourhood. Power company Tavanir reported some areas in the capital experienced electricity cuts.
LIMITED OPTIONS
Since the US joined Israel's campaign by dropping massive bunker-buster bombs on Iranian nuclear production sites on Sunday morning, Iran has repeatedly threatened to retaliate.
"Mr Trump, the gambler, you may start this war, but we will be the ones to end it," Ebrahim Zolfaqari, spokesperson for Iran's Khatam al-Anbiya central military headquarters, said on Monday in a recorded, English-language video statement.
"Iran was bound to retaliate so as not to appear to have surrendered and look weak," Dennis Ross, a former Middle East negotiator for both Democratic and Republican US presidents, wrote in a post on X. "But (Iranian Supreme Leader Ayatollah Ali) Khamenei knows, especially if Americans have not been killed, that there is a good chance to end the war with the US and to preserve the regime – always his 1st priority."
The Trump administration maintains that its aim is solely to destroy Iran's nuclear programme, not to open a wider war. But in a social media post on Sunday, Trump spoke of toppling the hardline clerical rulers who have been Washington's principal foes in the Middle East since Iran's 1979 Islamic Revolution.
Five insiders with knowledge of the discussions said efforts had been ramped up to anoint a successor for Iran's 86-year-old supreme leader, Ayatollah Ali Khamenei. His son Mojtaba, 56, and Hassan Khomeini, 53, grandson of the revolution's founder Ayatollah Ruhollah Khomeini, are now seen as the frontrunners, they said.
Americans are anxious over a brewing conflict between the US and Iran and worry the violence could escalate after President Donald Trump ordered the bombing of Iranian nuclear facilities, according to a Reuters/Ipsos poll that closed on Monday.
