Visa or Passport???

A passport is a US-issued document permitting you to travel abroad-this certifies your identity and citizenship. For the countries you listed, you need a passport. A visa is an entry permit, an endorsement of the country you are entering that the proper officials there have examined the document(passport). I do not know if that is required for the countries that you have listed. Visa is separate from passport and is a separate cost. If needed, there are usually different types, many times people will travel on a "tourist visa" for adoption versus "business visa" or "student visa" etc.Many agencies will help you obtain the visa, if needed.