Citizens of these countries are generally banned from applying for any new U.S. visa.
Afghanistan
Burkina Faso
Chad
Equatorial Guinea
Eritrea
Haiti
Iran
Laos
Libya
Mali
Myanmar (Burma)
Niger
Republic of the Congo
Sierra Leone
Somalia
South Sudan
Sudan
Syria
Yemen
Palestinian Authority-issued travel documents
Countries with Partial Entry Restrictions
Restrictions typically apply to specific nonimmigrant (e.g., visitor, student) and all immigrant visa categories.
Angola
Antigua and Barbuda
Benin
Burundi
Côte d’Ivoire
Cuba
Dominica
Gabon
Gambia, The
Malawi
Mauritania
Nigeria
Senegal
Tanzania
Togo
Tonga
Venezuela
Zambia
Zimbabwe
I feel like washing after just reading that.