US President Donald Trump has raised the possibility of a change in leadership in Iran, after his country joined Israel in striking Iranian nuclear facilities.

On Sunday, Trump posted on social media to ask “why wouldn’t there be a Regime change???”

His remarks came after other top US officials stressed that toppling Iran’s leaders was not the aim of Saturday’s military action, during which US bombers targeted three sites in an effort to curtail Tehran’s nuclear programme.

Trump has previously criticised US involvement in overseas conflicts, including in Iraq, where the US and its allies toppled the regime of Saddam Hussein in 2003.

In Sunday’s post, Trump wrote: “It’s not politically correct to use the term, ‘Regime Change,’ but if the current Iranian Regime is unable to MAKE IRAN GREAT AGAIN, why wouldn’t there be a Regime change???”

It appeared to put him at odds with his top allies. Over the weekend, Defence Secretary Pete Hegseth said the “mission was not and has not been about regime change” – a message that was echoed by Vice-President JD Vance.

Trump’s post caused a flurry of speculation, but one of his former officials questioned how seriously it should be taken.

Elliott Abrams, who was the American envoy to Iran during Trump’s first presidency, told BBC Radio 4’s Today programme there had been a lot of “misdirection” following the comments, and that Trump might just be “kidding around”.

Saturday’s strikes on three separate sites in Iran by the US came after a week of hostilities between Israel and Iran, triggered by an effort by Israeli Prime Minister Benjamin to wipe out Iran’s nuclear research programme.

Both Netanyahu and Trump voiced fears that Tehran was nearing a capacity at which it could build a nuclear weapon. Iran has repeatedly denied planning to do so.

Trump says the strikes – which used high-tech American “bunker-buster” bombs to attack underground infrastructure – caused “monumental damage”. However, the scale of the destruction is not yet clear.

The UN’s nuclear watchdog has called for a ceasefire in order to allow an inspection.

Iran responded furiously, vowing what it calls “everlasting consequences”.

On Monday morning, the Israeli military said missiles had been launched from Iran towards Israel. It also said it had attacked six airports in Iran.

There are 40,000 US soldiers on bases and warships in the Middle East who are now on high alert as officials brace for retaliation from Iran. The US Department of State has also issued a global warning, advising US citizens worldwide to exercise increased caution.

Iranian state TV has reported that the country’s parliament has also approved a measure to close Strait of Hormuz – a narrow route that is critical for trade.

Such a move could have major ramifications for global trade, since almost a quarter of the world’s oil and gas passing through it. US Secretary of State Marco Rubio has called on China to prevent Iran from making a closure.

Meanwhile, Iran’s foreign minister has travelled to Moscow to meet Russia’s President Putin to talk about their “common challenges and threats”.

The attacks over the weekend come after Trump repeatedly said on the presidential campaign trail last year that the US should not be involved in what he called “forever wars”.

In September, he said: “We will quickly restore stability in the Middle East. And we will return the world to peace.”

But supporters of the Republican president and opposition Democrats alike have pointed out that his recent actions in Iran could bring the US back into wars in the Middle East.

Congressman Thomas Massie, a Republican from Kentucky, called Trump’s actions “unconstitutional”.

“When two countries are bombing each other daily in a hot war, and a third country joins the bombing, that’s an act of war,” Massie wrote on social media, arguing the president should have sought congressional approval before getting involved.

Last week, before Trump’s intervention, Vance said he understood why people were worried about America getting involved in Iran “after the last 25 years of idiotic foreign policy”, but he argued that Trump had “earned some trust on this issue”.

In an apparent acknowledgement of the isolationist parties within his party, Vance added: “Having seen this up close and personal, I can assure you that [Trump] is only interested in using the American military to accomplish American people’s goals.”