SECRETARY of Homeland Security John Kelly has stepped in to approve entry to the US of Green Card holders as confusion reigns over immigration bans.
"I hereby deem the entry of lawful permanent residents to be in the national interest,” a statement issued by the Department of Homeland Security read.
It follows widespread confusion across US border and customs control points as teams attempted to interpret and apply Friday's executive order that halted entry to the US by people from seven Muslim-majority countries - Syria, Iran, Iraq, Yemen, Sudan, Libya and Somalia.
It was not clear at first whether this extended to Green Card and dual citizenship holders.
This had affected even pilots and aircrew of international flights who held appropriate papers, with Emirates reporting it had to adjust rosters urgently.
President Trump has launched an attack on two key Republican senators who expressed alarm at the chaos caused by his executive order. He took to Twitter to express anger at John McCain and Lindsey Graham.
"They are sadly weak on immigration,” Mr Trump said. "Senators should focus their energies on ISIS, illegal immigration and border security instead of always looking to start World War III”.
They had lashed out at the executive order, saying it "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,” their statement said.
"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.”
British business leaders have also spoken out against the ban.
The British Chambers of Commerce and the Institute of Directors said the ban would be bad for business.
An IoD spokesman said: "The sudden, severe and indiscriminate restrictions imposed on passport holders from seven Muslim countries could seriously undermine business and trade.
"Both in the US and the UK, a number of industries including tech rely heavily on highly skilled brainpower from across the world. If businesses are restricted from accessing workers then many companies may have to rethink where they place their key staff in future, and that would ultimately have consequences for the prosperity of that country.
British Prime Minister Theresa May has secured an exemption for Britons from the "Muslim ban” after frantic moves to prevent a backlash against the policy damaging her government.
A Foreign Office statement said: "The only dual nationals who might have extra checks are those coming from one of the seven countries themselves - for example a UK-Libya dual national coming from Libya to the US.
With additional reporting from INM