Donald Trump last night issued a chilling threat to Iran: make a nuclear deal or face an overwhelming military onslaught.

As the US President's 'beautiful armada' of warships moved into position, the Tehran regime said any attack would be 'an act of war'.

Facing unprecedented domestic pressures, President Trump looked to make good his promise to protect Iranians from the country's Supreme Leader Ayatollah Khamanei following a brutal crackdown on protests against the regime thought to have left tens of thousands dead. 

Having stepped back from the brink a fortnight ago when Tehran dropped threats to hang protesters, the President vowed the United States was ready to fulfil its mission in the region 'with speed and violence, if necessary'.

He warned that 'time is running out' for the mullahs to negotiate a deal on their nuclear programme, which was the subject of US attacks last year.

Iran's mission to the UN responded by saying Tehran 'stands ready for dialogue based on mutual respect and interests', but it would defend itself and 'respond like never before' if threatened.

Igniting the rhetoric further, Iran's foreign minister Abbas Araghchi warned that its armed forces had 'their fingers on the trigger to immediately and powerfully respond to any aggression'.

With the region back on the brink of conflict, the UK condemned Iran's 'brutal' repression, with Deputy Prime Minister David Lammy criticising the regime and backing sanctions.

However, whether any UK naval assets would take part alongside the US looked uncertain last night, following the Royal Navy's recent announcement that its last frigate is to return from the region.

In the early hours of yesterday, Mr Trump told a rally in Iowa: 'By the way, there's another beautiful armada floating beautifully toward Iran right now, so we'll see. I hope they make a deal. They should have made a deal the first time.'

He then followed it up with a message on his Truth Social platform: 'A massive Armada is heading to Iran. It is moving quickly, with great power, enthusiasm, and purpose.

'It is a larger fleet, headed by the great Aircraft Carrier Abraham Lincoln, than that sent to Venezuela. Like with Venezuela, it is ready, willing, and able to rapidly fulfill its mission, with speed and violence, if necessary.

'Hopefully Iran will quickly 'Come to the Table' and negotiate a fair and equitable deal – NO NUCLEAR WEAPONS – one that is good for all parties.

'Time is running out, it is truly of the essence! As I told Iran once before, MAKE A DEAL! They didn't, and there was 'Operation Midnight Hammer,' a major destruction of Iran.

'The next attack will be far worse! Don't make that happen again.'

Last summer, after weeks of Israel and Iran exchanging missiles, Mr Trump ordered Operation Midnight Hammer to target Tehran's nuclear facilities.

Seven B-2 stealth bombers flew 18-hour journeys to and from the US to drop their devastating payloads on plants buried deep into a mountain at Fordo.

Last night, US Navy and Air Force assets were awaiting his order to once again strike. The US was moving defensive missile systems into the region from bases in Europe, suggesting action could be taken any day.

Following Mr Trump's dramatic capture of Venezuelan president Nicolas Maduro as he seeks a new world order, his ambitions in Iran may not be limited to its nuclear facilities, according to security sources. 

The President is understood to have issued the regime in Tehran with three demands: to permanently end uranium enrichment, restrict its ballistic missile programme and end its support for proxy groups such as Hamas and Hezbollah.

Behind the scenes, the UK and France have offered support to the White House, in moves intended to restore relations damaged by the recent dispute over Greenland.

President Trump came close to ordering strikes against Iran earlier this month, at the height of the uprising against its regime. But he backed off after warnings from regional partners about Iran's anticipated response.

He had told the thousands of protesters demanding democracy 'help is on its way', then seemingly changed his mind, after the regime agreed not to execute 800 protesters.

Key US allies such as Saudi Arabia, Qatar and Egypt urged restraint and diplomacy, convincing Mr Trump to back off.

Unnamed US security sources have indicated the White House may be eyeing a similar operation to Venezuela whereby he is able to remove Iran's political leadership while leaving the infrastructure of government in place.

But the Supreme Leader is much better protected than the Venezuelan president. Iran has placed its military forces on high alert and has sent long-range drones over the Iranian Ocean to record the progress of the US warships.

There were also fears last night that Israel could bear the brunt of any Iranian military retaliation.

Ali Shamkhani, an adviser to Khamanei, pledged that any US action would be 'considered the start of war'. 

On X, he said: 'The response will be immediate, all out and unprecedented,' adding that 'all supporters of the aggressors' would be targeted. Iran's mission to the UN in New York taunted: 'Last time the US blundered into wars in Afghanistan and Iraq it squandered $7trillion and lost more than 7,000 US lives.'

President Trump could be using foreign policy to distract his critics from issues at home, such as the double killing of US citizens by ICE agents in Minneapolis.

The shooting death of nurse Alex Pretti's came a fortnight after poet and mother-of-three Renee Good was killed.

Former presidents and business leaders have spoken out against ICE's tactics.

Another US government shutdown was looming last night as rival Democrats vowed to block White House spending plans on Homeland Security passing through Congress if they include funding for ICE.

In a rare show of solidarity for the US, France last night confirmed it intended to list Iran's Republican Guards, the IRGC, as a terrorist group. The European Union is expected to follow suit.

The moves will place pressure on the UK to follow suit. Keir Starmer's Government has sanctioned the IRGC but has refused to proscribe the group as a terrorist organisation.

The Prime Minister's critics have accused him of threatening UK security by failing to make this move, but others have argued it would have no real value.

This month, the Royal Navy announced its intention to pull back its only warship in the Gulf.

The return of HMS Lancaster from Bahrain will end an offensive military presence in the region going back 46 years. Royal Navy minesweepers will continue to operate in the Gulf.