On Monday night, Donald Trump issued a stern warning to Iran, cautioning that a significant retaliation, referred to as the ‘big one’, could be imminent. He also expressed his willingness to deploy ground troops if the situation called for it.

The conflict widened on Monday, with Israel engaging in exchanges of fire with Hezbollah militants in Lebanon. Meanwhile, U.S. jets were reportedly shot down over Kuwait, and Qatar engaged in combat with Iranian fighter planes.

Trump predicted that the ongoing conflict might persist for “about four weeks,” but claimed that U.S. and Israeli forces were making swift progress and were “ahead of schedule” in their operations.

The U.S. President hinted at the possibility of deploying soldiers, asserting that they would be dispatched “if necessary.”

Despite his initial campaign promises to curtail U.S. involvement in foreign conflicts, Trump emphasized, “I don’t hesitate when it comes to considering boots on the ground.”

He further clarified his stance by stating, “Unlike other presidents who declare ‘there will be no boots on the ground,’ I remain open to the idea, saying ‘probably don’t need them,’ or ‘if they’re necessary.’

Such a move would likely result in more US casualties and could prove unpopular with President Trump’s supporters who favour US isolationism.

He warned Iran: ‘We haven’t even started hitting them hard’, adding ‘the big wave has not even happened, the big one is coming soon.’

A man carries an injured woman at the site of US-Israeli airstrikes in Tehran, Iran on Monday

Donald Trump on Monday night warned Iran that the ‘big one’ was coming as he said he was not afraid to put boots on the ground if needed

‘We’re knocking the crap out of them,’ he told CNN. ‘I think it’s going very well. It’s very powerful. We’ve got the greatest military in the world and we’re using it.’

His Secretary of War, Pete Hegseth, said America was ‘fighting to win’ on its terms and with ‘no stupid rules of engagements’.

While the US is apparently assisting anti-regime elements inside Iran, Mr Hegseth said America was not particularly interested in regime change, avoiding any ‘nation-building quagmire’ or any ‘democracy building exercise’.

‘We fight to win. And we don’t waste time or lives,’ he said.

‘Destroy Iranian offensive missiles, destroy Iranian missile production, destroy their navy and other security infrastructure, and they will never have nuclear weapons.

‘Iran was building powerful missiles and drones to create a conventional shield for their nuclear blackmail ambitions,’ he said. 

‘Our bases, our people, our allies, all in their crosshairs – Iran had a conventional gun to our head as they tried to lie their way to a nuclear bomb.’ 

US Secretary of State Marco Rubio said the operation needed to happen ‘no matter what’, claiming Iran would otherwise have ‘so many short-range missiles, so many drones, that nobody could do anything about it’.

Tehran has been pummelled by US and Israeli air strikes since Saturday, when they killed Ayatollah Khamenei

Israel launched a series of attacks on Lebanon after Hezbollah fired missiles at Haifa on Sunday

He added that the US attacked Iran ‘pre-emptively’ after learning of Israel’s plans to strike.

Asked about the future of the country, Mr Rubio said the US would ‘love’ Iranians to topple the government, although the objective was to destroy the country’s ballistic missile capability.

The US military said it had struck more than 1,250 targets in Iran since Saturday, adding that it had also destroyed 11 Iranian ships.

On Monday, the crews of three US jets had a fortunate escape when they were accidentally shot down by Kuwaiti air defences. All six pilots ejected safely. A video online showed Kuwaiti residents thanking one female pilot for her service after she landed.

Six US service personnel have been killed in the first three days of Operation Epic Fury.

On Monday night the conflict threatened to spread across the Middle East. Israel is poised to invade southern Lebanon while Qatar said it shot down two Iranian SU-24 fighter jets.

The Qataris were responding to a co-ordinated Iranian attack, which also included seven ballistic missiles and five drones.

The Gulf state condemned Iran for its ‘reckless and irresponsible’ actions.

Mr Trump said the ‘biggest surprise’ for him had been Iran’s attacks on Arab countries in the region.

‘We were surprised,’ the President said. ‘We told them [other countries], ‘We’ve got this,’ and now they want to fight. And they’re aggressively fighting. They were going to be very little involved and now they insist on being involved.’

Iran has also attacked Kuwait, the United Arab Emirates and Saudi Arabia following the US and Israeli military action that began on Saturday morning. The UAE suffered sustained bombardment on Monday as its defences intercepted nine ballistic missiles, six cruise missiles and 148 drones.

Pictured: The pilot of an F-15 fighter jet shot down over Kuwait was thanked by locals after managing to safely eject from the plane before it plummeted to the ground

According to figures released on Monday, the UAE has shot down 174 ballistic missiles since the attacks began, along with 689 Iranian drones.

The US embassy in Kuwait was hit by a suspected Iranian drone strike on Monday night. 

The US State Department said there were no injuries but the building’s exterior was damaged and an external warehouse was set on fire, according to the Washington Post. In Lebanon, the health ministry said 31 were killed by Israeli air strikes in southern Beirut where Hezbollah militants are based.

Israeli defence chief Lieutenant General Eyal Zamir said this was the start of an ‘offensive campaign’ against Hezbollah and residents should prepare for ‘many prolonged days of combat ahead’.