Sick children, families and businesses are among the many people in Haiti, a country plagued by gang violence, likely to be hit hard by a U.S. travel ban.

The Trump administration announced in a proclamation on Wednesday that it will ban nationals from Haiti from entering the United States and partially limit Cubans and Venezuelans from coming into the country.

President Donald Trump’s new ban on travel to the United States by citizens from 12 mainly African and Middle Eastern countries is now in effect.