A sweeping new travel ban on citizens from a dozen nations was announced by the White House on Wednesday, reviving a defining effort from the first Trump administration to crack down on entries from specific countries.

U.S. President Donald Trump's order banning citizens of 12 countries from entering the United States goes into effect at 12:01 am ET (0401 GMT) on Monday, a move the president promulgated to protect the country from "foreign terrorists.