Each applicant for a visitor visa must pay a nonrefundable US $100 nonimmigrant visa application processing fee which you can take with you to the interview.
Additionally, if the visa is issued, there will be an additional visa issuance reciprocity fee, if applicable. Please consult the government Visa Reciprocity Tables to find out if you must pay a visa issuance reciprocity fee and what the fee amount is. At the top of the page click on the letter that your home country’s name starts with and continue from there.