Iran will take a 'harsher revenge' on US troops in the Middle East after an initial rocket attack on Wednesday failed to kill anybody, a senior commander has warned.

Islamic Revolutionary Guard general Abdollah Araghi threatened further reprisals against the US on Thursday, despite Donald Trump saying the country 'appears to be standing down'.

Meanwhile air force commander Amir Ali Hajizadeh claimed that Iran had been prepared to launch 'hundreds' of missiles aimed at killing up to 5,000 Americans if Trump had decided to retaliate.

Amir Ali Hajizadeh, Iran's air force commander, claims he was ready to launch hundreds of missiles killing 5,000 Americans within hours - if Trump had retaliated to Wednesday's strike

Iran launched more than a dozen missiles at two bases in Iraq, including Ain al-Asad (pictured), but failed to kill a single soldier

Speaking on Iranian TV in front of a row of flags belonging to Iran-backed militias in the Middle East, Hajizadeh claimed that Iran was not aiming to kill anyone during the missile attack.

'If we were looking to kill, we could have designed the operation in a way such that 500 Americans would be killed in the first step,' he said.

'If they had responded, a further 4,000 to 5,000 would be killed in the next steps within 48 hours.'

He later added: 'We fired 13 missiles and were ready to fire hundreds more in case of any US response.

'We were prepared to respond to each response for days on end.'

Ayatollah Ali Khamenei yesterday called the missile strikes a 'slap in the face' against the US, before adding that 'the question of revenge is another issue.'

Yesterday Trump defended his targeting of Soleimani and said the general 'should have been terminated a long time ago'.

'Our great American forces are prepared for anything. Iran appears to be standing down, which is a good thing for all parties concerned and a very good thing for the world,' he said.

'The fact that we have this great military and equipment, however, does not mean we have to use it. We do not want to use it. American strength, both military and economic, is the best deterrent,' Trump said.

Islamic Revolutionary Guard general Abdollah Araghi said Iran would take 'harsher revenge soon' after Tehran launched missile attacks on U.S. targets in Iraq (pictured)

Donald Trump said the Iranian regime 'appears to be backing down' following Wednesday's strike, and said he doesn't want to carry out any more strikes against them

Trump said the United States 'will immediately impose additional punishing economic sanctions on the Iranian regime' in response to what he called 'Iranian aggression.'

Iran will likely order more militia attacks and target countries cyber networks after 'revenge', says Middle East Expert By Luke Andrews for MailOnline The Iranian regime will likely swing back to its 'strategic unconventional playbook' involving militia attacks and the targeting of other countries cyber networks, a Middle East expert has claimed. Security expert at the University of Exeter, Tallha Abdulrazaq, also told MailOnline that he expects a continued 'menacing' of America's Arab allies. 'The Iranian leadership's military response to the US killing of Qassem Soleimani fell far short of the vengeance they promised but provided them with an off-ramp to de-escalate with the US by appearing to retaliate while causing as little damage as possible to avert a massive American response,' he said. 'Iranian agitation (will likely be) carried out through terrorist groups such as Hezbollah in Lebanon on the Israeli border, increased Shia militant attacks in Iraq and Syria, and a general menacing of Saudi Arabia and other Arab allies of the United States. 'Small scale cyber attacks have also been a feature of Iranian activity in recent days, so we can expect more sophisticated attacks in the future.' It comes after Iran's 'revenge' attack on two Iraqi bases containing US soldiers failed to kill a single American soldier. Advertisement

The president also proposed a new deal with Iran, saying: 'We must all work together toward making a deal with Iran that makes the world a safer and more peaceful place.'

Iran's ambassador to the United Nations today dismissed Trump's call for co-operation as 'unbelievable'.

More than a dozen ballistic missiles hit the Al Asad air base in western Iraq and the Erbil base in Iraqi Kurdistan during Wednesday's strikes.

Iran warned Iraq about the raids shortly before they happened, the Iraqi prime minister said yesterday.

Adel Abdul Mahdi said Iran's tip-off was passed on to the bases where troops were able to take shelter in their bunkers.

Mahdi said Iran did not give specific locations to him but said they would only target locations where U.S. forces were present.

As the missiles were raining down, Mahdi said he received a call from Washington to say they already knew of the assault.

In their immediate aftermath, foreign minister Mohammad Javad Zarif said Tehran had concluded its 'proportionate' retaliation.

US Defense Secretary Mark Esper cautioned that the U.S. military remained 'poised and ready.'

At least 11 of them hit al-Asad, while at least one other missile hit a facility in Erbil, Iraq. The others failed in flight. Esper said targets hit included tents, a helicopter and a parking lot and there was no major damage.

Army General Mark Milley said the missiles had 1,000 to 2,000-pound warheads on them, each with significant explosive power and 'kill radius.'

'I believe, based on what I saw and what I know, is that (the strikes) were intended to cause structural damage, destroy vehicles and equipment and aircraft and to kill personnel. That's my own personal assessment,' Milley told reporters.

'But the analytics is in the hands of professional intelligence analysts. So they're looking at that.'

Esper and Milley said they were unaware of any heads-up from Iraq about the coming attack, after Baghdad said it was notified by Tehran of the strike.

In a separate report, Tasnim news agency quoted the deputy Guards head, Ali Fadavi, as saying Iranian missile attacks on U.S. targets were a display of Iran's military power and said U.S. forces 'couldn't do a damn thing.'

Soleimani, who was seen as a hero in Iran but regarded as a terrorist leader by the US, was killed him in a drone strike near Baghdad airport last Friday.

His death already has pushed Tehran to abandon the remaining limits of its 2015 nuclear deal, and a series of top Iranian officials have sworn revenge on Washington.

Iranian state TV said the country would no longer respect any of the limits in the deal, which Trump has abandoned but European powers want to preserve.

Under the deal, Tehran had pledged to reduce its nuclear capacities for several years, including by capping its enrichment of uranium at 3.67 percent, far below the more than 90 percent required for a nuclear weapon.

Iran has already overstepped some of the limits since Trump pulled out of the deal in May 2018.