US President Donald Trump is defending his executive order restricting travel from seven Muslim-majority nations amid confusion, angst and protests at airports in several major cities.
In a statement issued on Sunday evening, Trump said the decision is to block people from entering the country, and is not about religion but security.
However, Trump's order has prompted confusion at airports worldwide, and in the US as authorities adjust to the directive.
Federal judges have granted temporary reprieves in certain cases. Green card holders - US residents who are not citizens - have been concerned whether they would be allowed to return to their homes and families in the US.
US Homeland Security authorities said on Sunday that green card holders from the countries in question would not necessarily be sent back once they arrive, but processed on a case-by-case basis.
TRT World 's Tetiana Anderson went to Dulles International Airport in Washington DC to see what was happening.