The new proclamation, which Trump signed on Wednesday, applies to citizens of Afghanistan, Myanmar, Chad, the Republic of Congo, Equatorial Guinea, Eritrea, Haiti, Iran, Libya, Somalia, Sudan and Yemen. It also imposes heightened restrictions on people from Burundi, Cuba, Laos, Sierra Leone, Togo, Turkmenistan and Venezuela who are outside the U.S. and don’t hold a valid visa. It does not revoke visas previously issued to people from countries on the list.