Preparations for possible action have been under way this week, according to Sky News' partner network NBC News.
The Pentagon has tailored options to meet the president's objectives, and they were due to be presented to him on Wednesday, two US officials and a person familiar with the discussions said.
The US has already begun withdrawing some military personnel from its Al Udeid Air Base in Qatar, the biggest American military base in the region. Sky News understands UK personnel were also leaving the same base.
Mr Trump declared earlier this week that "help is on its way" for Iranian protesters who have been met with a brutal crackdown from the regime, fuelling expectations of US military intervention.
A total of 2,615 people have been killed in the demonstrations, which began last month, according to the US-based Human Rights Activists News Agency, though other reports have suggested a much higher number.
Mr Trump also promised to take "very strong action" if the regime in Tehran goes ahead with executing protesters.
But speaking in the Oval Office on Wednesday, he claimed he'd been told the "killing in Iran is stopping".
A family member of one of those facing execution, Erfan Soltani, told Sky News there was no official announcement about his status on Wednesday.
But they added that Mr Soltani, 26, who was reportedly arrested last Thursday, could still face execution at any time.
Iran's foreign minister Abbas Araghchi claimed in a Fox News interview that no executions were planned.
'Any regime can fail'
In an interview with Reuters news agency, Mr Trump said he believed the protests could lead to the fall of the regime, which has been in place since the revolution of 1979.
"Any regime can fail," he said, adding: "Whether or not it falls or not, it's going to be an interesting period of time."
But he expressed doubt as to whether Iran's exiled crown prince, who has become a prominent voice spurring on protesters, could take over.
Mr Trump said Reza Pahlavi "seems very nice, but I don't know how he'd play within his own country".
Read more: Who is Crown Prince Reza Pahlavi?
Elsewhere, America's Western allies remain concerned about the situation across Iran.
The British embassy in Tehran has been temporarily closed, and the Foreign Office said it had "taken the precautionary measure to temporarily withdraw UK staff from Iran".
The UK already advises against all travel to the country.
Foreign ministers from the G7 group of nations, which includes the UK, also issued a joint statement on Wednesday to stress they were "gravely concerned by the developments surrounding the ongoing protests".
"The members of the G7 remain prepared to impose additional restrictive measures if Iran continues to crack down on protests and dissent in violation of international human rights obligations," the statement added.
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Meanwhile, Iran has now been cut off from nearly all telecommunications for more than six days, according to internet monitoring organisation NetBlocks.
The government began blocking internet access and international calls last Thursday as protests intensified.
Weeks after Justice Secretary David Lammy declared the measures would not be retrospective, the courts minister Sarah Sackman has doubled down on the reforms.
She told Sky News that where a trial date has not been set, "what you want is those measures to kick in straight away, so they can bring down the backlog".
This is likely to inflame the row over the changes, with the Bar Council arguing it could breach a fundamental legal principle and may result in a legal challenge.
Mr Lammy and his team are proposing that if MPs and peers agree, soon almost all crimes with a penalty of up to three years in prison will be tried by only a single judge - with no option to opt for a jury.
In one of the strongest outbursts by a mainstream Labour MP about the party leadership in years, Karl Turner, the lawyer leading the rebellion, said he was "ashamed" of Sir Keir Starmer, called Mr Lammy "lazy", and told Sky News the government needed to realise he and colleagues may end up quitting the Commons.
"At least 60" Labour colleagues are also willing to rebel over the plans, according to the Hull MP, reaching a tipping point where "it's not difficult for five more and 10 more and 15 to come on board because you've got the security of the numbers".
"The chief whip can't start suspending 80 members," he added.
He warned that if he was threatened, he could end up saying "I've had enough, I'm off" - triggering a by-election.
His comments feature in a Sky News investigation into the courts system, as part of a series about whether politics is breaking or mending the UK.
We witnessed hours of court sitting time at Snaresbrook Crown Court taken up by missing paperwork, lawyers, and defendants.
We saw offenders unable to undertake rehabilitation courses, arrest warrants not entered in the police computer system, and court staff using their personal email to order psychiatric reports.
No sign of compromise despite backlash
A recently retired judge criticised the government's plans, which hand judges more power.
"At the moment, judges have quite enough power," Christopher Kinch KC, an ex-senior circuit judge, told Sky News.
"I've always thought an important part of the whole process was that having decided the framework and the shape of the case, the judge then said 'this is too important for me, and it's over to you as 12 members of the public'."
Senior lawyers refused to rule out strike action over the proposal to roll back jury trials in some cases.
Simon Spence KC, from the Criminal Bar Association, said: "I don't think we as a profession are going to rule anything out. They conducted a survey and found over 85% of those who responded said that they were opposed to the abolition or reduction of jury trials."
The courts minister definitively rejected a compromise reform plan, floated by government sources, that would see cases being heard by a judge and two magistrates.
Ms Sackman said: "We think the judge-only proposal is robust. It's what they do in Canada. I've got confidence in our judges to be able to run this."
The courts minister also revealed the government would press ahead by stripping some people already facing trial from their right to a jury.
She said: "In terms of the measures themselves, while cases that already have a trial date set for a jury or are already in train, of course those will have to proceed.
"But cases that are already in the system where a trial date hasn't been set, these measures will apply to those because what you want is those measures to kick in straight away so they can start to bring down the backlog."
Ms Sackman did not say Mr Lammy was wrong when he previously said the measures would not be retrospective, but had been answering a question "in a different context".
However, the Bar Association warned this could violate the principle of "lex mitior", which means that such a rule should not be applied retrospectively.
"The government will need to be clear on the cut-off point for commencement of provisions," said a source.
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Some 39 MPs signed a letter before Christmas suggesting they might rebel.
Mr Turner, who is co-ordinating the rebellion, told Sky News: "I'm not going to be bullied by threats of losing whips or anything else. It's taken me 16 years to lose my temper at a government policy.
"I'm only sorry that it's my own government, led by Keir Starmer, King's Council, who has built his professional career on a brilliant reputation of being an incredibly impressive eminent lawyer and, sadly, a human rights lawyer.
"So, when I say I'm ashamed of Keir Starmer, I mean it."
Pressed on what he would do if the legislation passes, he said: "The question is: is there going to be a by-election? What I've said to the chief whip is 'don't ring me to lecture me and threaten me with suspension from the Labour whip'. I don't care.
"My integrity is more important to me. But what you do need to worry about, Mr (Jonathan) Reynolds (the chief whip) is the fact that Labour MPs like me are sick to the back teeth of being marched up hills only to be marched back down again when the penny drops that the proposals that have been put forward by way of policy, which were not in the manifesto, which were a shock to us, are sprung on us like a rabbit from a hat.
"I'm fed up with it. All the Labour MPs are fed up with it, and you've got to concern yourself about some of us saying, 'I've had enough, I'm off'."
"We have implemented technological measures to prevent the Grok account from allowing the editing of images of real people in revealing clothing such as bikinis," said a statement.
"This restriction applies to all users, including paid subscribers."
It comes amid mounting condemnation in the UK and US of the chatbot's image editing capabilities, with British government ministers threatening the platform with action.
Sir Keir Starmer has described nonconsensual sex images produced by Grok as "disgusting" and "shameful", and media regulator Ofcom has launched an investigation.
The statement from X came hours after California announced its own state-level probe into the spread of sexualised images created by Grok, including of children.
Speaking at PMQs on Wednesday, Sir Keir had suggested action by the company may be imminent, telling MPs: "I have been informed this morning that X is acting to ensure full compliance with UK law.
"If so, that is welcome, but we're not going to back down, and they must act."
The controversy had seen X, which was bought by Mr Musk in 2022 when it was called Twitter, threatened with a potential fine or even ban in the UK.
Mr Musk, the billionaire owner of SpaceX and Tesla who has previously called for Sir Keir to be voted out of office, has claimed - along with Reform leader Nigel Farage - that a ban would be an attack on free speech.
Musk defends Grok safety measures
After the prime minister's comments at PMQs, Mr Musk wrote on X he was "not aware of any naked underage images generated by Grok".
"Obviously, Grok does not spontaneously generate images, it does so only according to user requests," he said.
"When asked to generate images, it will refuse to produce anything illegal, as the operating principle for Grok is to obey the laws of any given country or state.
"There may be times when adversarial hacking of Grok prompts does something unexpected. If that happens, we fix the bug immediately."
X had already announced in an earlier response to the political pressure that image creation and editing would be restricted to paid subscribers.
Technology Secretary Liz Kendall dismissed the move as merely "monetising abuse" and said the government would support Ofcom in whatever action it decides to take.
Ofcom's powers fall under the Online Safety Act, which states that online platforms have to make sure they're not hosting illegal content.
If X is found to not comply with the Online Safety Act, Ofcom can issue a fine of up to 10% of its worldwide revenue or £18m, and if that is not enough, can go as far as getting a court approval to block the site.
This "live play" is only an exercise - but the scenario is designed to test the UK's emergency response to a very real threat.
Firearms officers, hostage negotiators and paramedics must decide what to do over the next five hours as the Islamist militants turn the multiple decks of the Brittany ferry - carrying around 300 terrified passengers - into a warzone.
Sky News was given exclusive access to the drama at Poole Harbour on Wednesday.
"It's a really important opportunity for us to develop our plans, to test those plans, to strengthen our response," said Assistant Chief Constable Andy Hill, Counter Terrorism Policing South West.
"Ultimately we need to be able to respond should the worst happen."
The attack begins
The simulated crisis - which is not based on any specific intelligence or threat - began with an alert from the Coastguard at around 9am that a group of gunmen had launched an attack on a vehicle and passenger ferry as it crossed the English Channel from France.
Urgent messages sent by some of the people onboard revealed that the militants were opening fire at passengers. There are deaths and injuries.
With the ferry headed for Poole, Counter Terrorism Specialist Firearms Officers (CTSFO) from across the region are mobilised, along with hundreds of other emergency responders, including paramedics and firefighters.
A Coastguard helicopter swoops overhead as a ramp from the shore is lowered to enable armed police to race on to one of the decks, where vehicles would usually be stowed.
The lifeless bodies of two or three victims are already visible.
How do police respond?
Needing to regain control of the ferry, the teams break off to search the many floors, including cabins, open-plan seating areas and a canteen.
The counterterrorism officers are in constant communication over radios with a control centre on shore, relaying what is happening.
They are alerted to a stand-off on the bridge - the part of the ferry where the captain commands the vessel.
He has been taken hostage.
For the rescue team, finding his location is difficult.
A member of the crew offers to lead the way.
"We have a walking map," one of the police officers says.
She guides them up to a closed door that leads to the bridge.
Without hesitation, the armed police burst inside, shooting dead a hostage-taker and rescuing the captain.
"I am OK," the captain says. "I was held for about 45 minutes."
Leaving officers behind to secure the scene, the rest of the team push on to one of the other decks where lines of individual cabins stretch along a labyrinth of corridors.
They need to establish whether any attackers are hiding in the cabins - all of which are locked. The police use key cards to open the doors, one after another.
Suddenly they find a militant inside one of the rooms, holding a wounded woman hostage.
Caught by surprise, he surrenders and the lady - with a stab injury to one of her arms - is saved.
But the nightmare is still not over.
At another end of the ferry, two more gunmen have seized around 20 passengers and barricaded themselves in a room.
One of the attackers demands to speak with a negotiator.
Police negotiators move forward, protected by armed officers, including one holding a bullet-proof shield.
The militants, who appear to sympathise with Islamist terrorist groups such as Islamic State, make various demands to end the siege.
The police team try to reason with them, but the attackers become agitated.
The hostages can be heard crying out in fear, as they are threatened with being beheaded.
With the situation deteriorating, a decision is taken to storm the room.
Within seconds, the two attackers are dead.
But the police need to be sure no one else is hiding amongst the passengers. They order everyone to hold their hands in the air or put them on their head.
Crisis over, the tension eases, especially for the passengers, who are all civilian volunteers, including teenagers.
'Let's pray it never happens'
"I knew that it was acting and that we were safe, but it was kind of, how can you say, intimidating," said one 16-year-old student, called Viktoria from Germany.
Older people also took part such as Bernadette, 66, a police volunteer. "It was scary at first because it's all quiet, and then it just happens - like that," she said.
Bernadette said she wanted to take part to contribute to her local community's resilience.
"It really is a great opportunity and if it does happen, let's pray it never does, but if it does, we know we're ready in Dorset."
In total, six pretend militants took part in the attack. At least three were killed and two captured. The fate of the final man was unclear.
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There were multiple casualties, among them dead and seriously wounded.
The exercise, which involves police, paramedics, firefighters, and the Coastguard, will formally conclude on Thursday.
Speaking at the annual London government dinner at Mansion House this evening, Sir Sadiq will argue that London must actively shape the AI revolution to protect jobs, boost productivity and safeguard the capital's economy.
He will call for faster regulation, skills reform and leadership to ensure AI benefits society rather than deepening inequality.
"Used responsibly, AI could enable us to transform our public services, turbocharge productivity and tackle some of our most complex challenges," he is set to say as he announces a new AI taskforce and free AI training.
"But used recklessly, it could usher in a new era of mass unemployment."
AI impact 'will be colossal'
The Labour mayor will say there is a "moral, social and economic duty to act", with a choice to make: "Seize the potential of AI and use it as a superpower for positive transformation and creation, or surrender to it and sit back and watch as it become a weapon of mass destruction of jobs."
"The impact of AI on London's labour market will be nothing short of colossal," he will add.
"That is likely an underestimation.
"Without proactive action, old roles may disappear faster than new ones are created."
The mayor will say entry-level jobs are likely to be the first to go and, unlike the Industrial Revolution, those in white collar jobs will feel it the most.
That will include some of London's biggest sectors, such as finance, professional services and the creative industries.
He will put London forward as a global leader in AI, saying the tech shaping the future needs to be made in the capital "with our values hardwired into the code".
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On the London Taskforce on AI, he will say it will provide recommendations for what is needed to "embed AI skills at every level in our workforce and equip the next generation with the tools they'll need to thrive".
Sir Sadiq will also announce free AI skills courses open to all Londoners so they can "take advantage of this new technology".
But he will also warn there needs to be responsible regulation of AI, with lessons learned from the "social media revolution" that has saddled the UK "with a youth mental health crisis and a surge in online abuse".
"This time, we need to move faster and not make the same mistakes again," he will say.