During his campaign, Mr Trump repeatedly stated he would build the wall with Mexico to combat "drug dealers, criminals and rapists" and, in the wake of the San Bernadino terror attack, proposed a temporary ban on Muslims entering the United States.

Sean Spicer, the White House spokesman, said on Tuesday: "First and foremost, the President's been very, very clear that we need to direct agencies to focus on those who are in this country illegally and have a record - a criminal record or poses a threat to the American people. That's where the priorities going to be."

Detractors could launch legal challenges to the moves if all the countries subject to the ban are Muslim-majority nations, said immigration expert Hiroshi Motomura at UCLA School of Law. Legal arguments could claim the executive orders discriminate against a particular religion, which would be unconstitutional, he said.