President Donald Trump accused senators John McCain (R-AZ) and Lindsey Graham (R-SC) for trying 'to start World War III' after they released a joint statement criticizing his ban on immigration.

The two senators slammed Trump's executive order restricting travel to the US from seven predominantly Muslim countries, saying his failure to properly vet the policy led to widespread confusion at airports across the country.

They attacked Trump for punishing innocent people and questioned its efficacy, saying: 'We fear this executive order will become a self-inflicted wound in the fight against terrorism.'

The president fell back on his usual tactic against critics and suggested they focus their energies elsewhere 'instead of always looking to start World War III.'

President Donald Trump accused senators John McCain (R-AZ), left, and Lindsey Graham (R-SC), right, for trying 'to start World War III'

The two senators slammed Trump's executive order, saying it was not properly vetted and would likely spur terrorist recruitment rather than improve homeland security

Trump signed an executive order on Friday barring any non-U.S. citizen traveling from Iraq, Syria, Iran, Sudan, Libya, Somalia or Yemen from entering the United States for 90 days.

The move, which also affected legal permanent residents and visa-holders from those seven countries, sparked an outrage as protesters gathered across the country.

The ACLU won a temporary legal battle halting deportations, but more than 100 people were detained for hours before they were allowed into the US.

McCain and Graham's statement said: 'It is clear from the confusion at our airports across the nation that President Trump's executive order was not properly vetted.'

They also expressed concerns that the Departments of State, Defense, Justice and Homeland Security were not consulted on the matter.

'Such a hasty process risks harmful results,' they said.

The statement supported green-card holders, interpreters who served the US military, and 'refugees who have been shown through extensive vetting to pose no demonstrable threat to our nation, and who have suffered unspeakable horrors, most of them women and children.'

The two Congressmen went even further in their criticism, saying Trump's executive order could likely have the opposite effect on homeland security as a result of discrimination.

The president fell back on his usual tactic against critics and suggested they focus their energies elsewhere 'instead of always looking to start World War III'

Trump denied accusations of religious discrimination. The executive order bars any those from seven predominantly Muslim countries from entering the US for 90 days

Trump doubled down on his policy on Sunday, and members of his staff defended the president on TV appearances, at times looking flustered

They wrote: 'Ultimately, we fear this executive order will become a self-inflicted wound in the fight against terrorism...

'Our most important allies in the fight against ISIL are the vast majority of Muslims who reject its apocalyptic ideology of hatred.

'This executive order sends a signal, intended or not, that America does not want Muslims coming into our country.

'That is why we fear this executive order may do more to help terrorist recruitment than improve our security.'

Trump denied accusations of religious discrimination, insisting that it was not a 'Muslim ban'.

He said: 'This is not about religion – this is about terror and keeping our country safe. There are over 40 different countries worldwide that are majority Muslim that are not affected by this order.'

Trump lashed out at the two for speaking out, saying they were flat out 'wrong' and ' sadly weak'.

He tweeted: 'The joint statement of former presidential candidates John McCain & Lindsey Graham is wrong - they are sadly weak on immigration.

'The two senators should focus their energies on ISIS, illegal immigration and border security instead of always looking to start World War III.'