U.S. green card holders will require additional screening before they can return to the United States, the White House said on Saturday.

Earlier, a Department of Homeland Security official said people holding green cards, making them legal permanent U.S. residents, were included in President Donald Trump’s executive action temporarily barring people from seven Muslim-majority countries from entering the United States.

‘It will bar green card holders,’ Gillian Christensen, acting Department of Homeland Security spokeswoman, said in an email.

A senior White House official later sought to clarify the situation, saying green card holders who had left the United States and wanted to return would have to visit a U.S. embassy or consulate to undergo additional screening.

‘You will be allowed to re-enter the United States pending a routine rescreening,’ the official said.

Confusion abounded at airports as immigration and customs officials struggled to interpret the new rules, with some legal residents who were in the air when the order was issued detained at airports upon arrival.

The ban affects travelers with passports from Iran, Iraq, Libya, Somalia, Sudan, Syria and Yemen.

The official argued the pause on travel from the countries is a response to concerns that immigration and refugee programs are being abused. The Trump administration is developing stricter rules for vetting people who want to come to the United States.

Immigration lawyers, human rights groups and some U.S. senators have sharply criticized the order, which already faces legal challenges.

The executive order also seeks to prioritize refugees fleeing religious persecution, a move Trump separately said was aimed at helping Christians in Syria, leading some legal experts to question whether the order was constitutional.

Asked about lawsuits, the official said foreigners do not have a right to enter the United States, and dismissed as ‘ludicrous’ critics' claims that the order is directed at Muslims.

Afghanistan, Malaysia, Pakistan, Oman, Tunisia and Turkey were Muslim-majority countries not included in the order, a second official said.