Donald Trump and his Iranian foes were urged by Britain to step back from the brink of all-out war today after a US airstrike took out a top Tehran general in Iraq.

Foreign Secretary Dominic Raab urged restraint from both sides amid talk of revenge for the targeted killing of Revolutionary Guard General Qassem Soleimani in Baghdad.

As British troops in the region were placed on high alert amid fear of reprisals after the attack, he warned against escalation in the volatile region.

It came as Boris Johnson came under pressure to cut short his New Year holiday in the Caribbean to deal with the crisis.

It is believed the UK was not warned about the airstrike in advance.

In a statement this morning, Mr Raab said: 'We have always recognised the aggressive threat posed by the Iranian Quds force led by Qasem Soleimani.

'Following his death, we urge all parties to de-escalate.

'Further conflict is in none of our interests.'

The UK is thought to have around 400 troops in Iraq, training its security forces to fight Islamic State, and more in Jordan and the Gulf.

Outgoing Labour leader Jeremy Corbyn said the 'US assassination' was an extremely serious and dangerous escalation of conflict in the Middle East with global significance'.

He said: 'All countries in the region and beyond should seek to ratchet down the tensions to avoid deepening conflict, which can only bring further misery to the region, 17 years on from the disastrous invasion of Iraq.'

Mr Johnson was under pressure today to cut short his post-election break to deal with any fallout from the assassination

An American airstrike on Baghdad airport has killed Qassem Soleimani, the head of Iran's powerful Quds force, and Abu Mahdi al-Muhandis, the deputy-leader of Iraq's Popular Mobilization Forces (pictured, the burning remains of a car that was among a convoy the men had been travelling in)

The death of Soleimani (left), a figure deeply ingrained in the Iranian regime who many had assumed would be the country's next leader, brings Iran and America to the brink of all-out war. Abu Mahdi al-Muhandis had been instrumental in leading attacks on the US embassy (pictured right, outside the building)

As the sun rose over Baghdad airport, daylight revealed the twisted remains of one of the vehicles the men had been travelling in. In total, a US drone fired four missiles that struck a convoy of cars, killing the two men and their entourage

Foreign Secretary Dominic Raab urged restraint from both sides amid talk of revenge for the targeting killing

British and American flags were burned by demonstrators protesting in Tehran against the killing this morning

British MPs criticised the 'reckless' attack and warned it would lead to 'severe consequences'.

US confrontation with Iran is foreign test for PM when he wants to focus on Brexit The attack by the US on Iranian military leaders in Iraq will prove an early diplomatic test for the prime minister at a time when he will want to be focusing on Brexit and the rest of his domestic agenda. Depending on whether there is any escalation and in what form, Britain's role is likely to be diplomatic, attempting to ease tensions in a volatile region responsible for the vs majority of the world's oil production. Iranian fury may be aimed at Donald Trump and the United States over the killing of General Qassem Soleimani but that anger could easily spread to include Britain. The UK is a longstanding and key ally of the US in the Middle East, from the invasion of Iraq that toppled Saddam Hussein in 2003 to the ongoing fight against Islamic State. British troops have been present in the area for 17 years and some 400 are still in Iraq, training its security forces to fight groups including Iranian-backed militias. There are also around 500 personnel at RAF Akrotiri in Cyprus where fast jets and reconnaissance planes fly out over Iraq and Syria. But Britain also attracts extra anger from Tehran, with what it sees as a long history of interference in its politics in the 20th century, prior to the 1979 Islamic revolution. Relations have been heavily strained in recent years, with the the British embassy sacked by demonstrators in 2011 after the UK backed increased actions against the hardline Islamist regime, which continues to talk tough over the development of nuclear weapons. The consulate only reopened again in 2015. More recently relations have been strained by the row over the nuclear sanctions. And there is also the continued incarceration of dual-national Nazanin Zaghari-Ratcliffe on spying charges widely seen as trumped-up. Her case was not helped by several gaffes by Mr Johnson when he was foreign secretary. Richard Ratcliffe, Nazanin's husband, said: 'Things are getting much worse again between the US and Iran, but also between all of us and Iran.' He told ITV's Good Morning Britain: 'I sit here partly worried for what that means for Nazanin, partly worried what that means for my in-laws, sat in their ordinary living room in Tehran where they're all really worried.' Advertisement

Labour's Jess Phillips, who is being tipped to run to replace Mr Corbyn as party leader, said: 'Reckless foreign policy does not show strength. It's not a game.

'The consequences of the escalating tensions between the US and Iran are not to be underestimated, not just once again on the civilians in the region but on the whole world.'

Fellow Labour leadership hopefuls also weighed in, with Wigan's Lisa Nandy adding: 'This is a very dangerous moment. 17 years after the catastrophic decision to go to war in Iraq violence still rages every day.

'World leaders must stand up to Trump. The last thing we need is another all-out war.'

And Tory backbencher MP David Jones said: 'The killing of the leader of Iran's Quds Force, Qassem Soleimani, will undoubtedly lead to severe consequences in the region.

'It is essential that the Western powers remain mindful of the interests of the ordinary people of Iran.'

Gen Soleimani, the powerful head of Iran's elite Quds Force, was killed at Baghdad International Airport, US officials confirmed.

Abu Mahdi al-Muhandis, the deputy commander of Iran-backed militias in Iraq known as the Popular Mobilization Forces, which were responsible for the recent attack on the US embassy in Baghdad, was also killed.

After the strike the Pentagon released a statement saying: 'At the direction of the President, the U.S. military has taken decisive action to protect U.S. personnel abroad by killing Quasem Soleimani.'

Soon after news of the strike spread, Trump, who is currently at his Mar-a-Lago golf resort in Florida, tweeted an image of an American flag, offering no further remarks or explanation.

Iran called the strike an act of 'international terrorism' and the country's supreme leader Ayatollah Ali Khamenei vowed that 'harsh revenge is waiting for the criminals' who killed Soleimani.

The Islamic Revolutionary Guard Corps confirmed the killing, saying the general had been 'martyred in an attack by America'.

The leader of Lebanon's Tehran-backed Hezbollah group called for General Soleimani's death to be avenged, in a sign that the attack could have repercussions across the Middle East.

'Meting out the appropriate punishment to these criminal assassins... will be the responsibility and task of all resistance fighters worldwide,' Hassan Nasrallah said in a statement released today.

Iraqi PM Adel Abdul Mahdi said the air strike was an act of aggression on Iraq and a breach of its sovereignty that will lead to war in Iraq, the region, and the world.

Labour's Jess Philips said that 'reckless foreign policy does not show strength', while Tory backbencher MP David Jones said the killing 'will undoubtedly lead to severe consequences in the region'

Boris Johnson and girlfriend Carrie Symonds arrived on the Caribbean island of Mustique on Boxing Day and spent the new year in a £20,000-per week hideaway, after flying economy (pictured)

The couple are understood to have landed at a nearby island before taking another plane and arriving at Mustique. The villa they are staying at boats three private pools, a butler, chef and housekeeper

Shadow justice secretary Richard Burgon, who is running to become Labour's deputy leader, warned of the consequences of an all-out conflict, saying: 'More than ever we need to avoid being the sidekick of Donald Trump.'

He added: 'There is a real risk of Trump engaging in a war with Iran that would be even worse than that on Iraq.

'We need an international movement against war and for peace. In increasingly dangerous times, it's vital our party plays its role in that movement.'

Former Middle East minister Alistair Burt has said the US launching an airstrike which killed Iran's most powerful military commander General Qasem Soleimani is 'extremely serious' and put UK military personnel at greater risk.

Mr Burt told BBC Radio 4's Today programme: 'Any action where you cannot foresee immediate consequences, take steps to prevent the most difficult consequences, you know, puts the region on edge and makes life more difficult for everyone.

'It's very hard to see what the consequences will be. I'm quite sure the United States will have to come out with more justification for its actions - what has caused this.

'But I think everyone has got to have extremely cool heads this morning. This is a very grave escalation in the affairs of the region, the consequences are unknowable and I think words and comments have got to be extremely carefully handled today.'

Asked whether the UK Government would have been told about the US government's airstrike plans before they happened, Mr Burt added: 'I doubt it.'