Many Americans traveling abroad find that it is necessary to travel to an American Embassy or Consulate in order to request services such as Passport renewal, adding of visa pages, notarial services, or Consular Reports of Birth Abroad (CRBA). Many of these requests can be made at an American Citizen Services Section of the US Embassy or US Consulate-General.

Meanwhile, every year many foreign nationals from around the globe travel to American posts abroad to apply for visas and other travel documents granting permission to travel to the United States. Some visa seekers only wish to remain temporarily in the US on non-immigrant visas such as the B-1 visa (Business Visa), the B-2 visa (Tourist Visa), the F-1 visa (Student Visa), or the J-1 visa (Exchange worker visa). Generally, applications for the aforementioned visa categories can be made at a non-immigrant visa unit within the Consular Section of the US Embassy or US Consulate-General. Applicants are usually required to make an appointment in advance to apply for these types of visas.

Some foreign nationals wish to travel to the United States for business purposes. Depending upon the circumstances of the individual applying for admission to the USA, a business traveler may be issued a non-immigrant or an immigrant visa. The L-1 visa, the E-1 visa, the E-2 visa, the EB-5 visa, the EB-4 visa, the EB-3 visa, the EB-2 visa, the EB-1 visa, and the H-1B visa are all business visa categories commonly sought by foreign nationals. Generally, a business travel unit  within the Consular Section of a US Embassy or Consulate-General abroad is responsible for adjudicating such applications.

Some foreign nationals seek visa benefits based upon a relationship to a US Citizen or lawful permanent resident. One of the most commonly sought US family based visas is the immigrant visa based upon marriage to an American Citizen, these types of visas are generally classified as a CR-1 visa or an IR-1 visa. Fiancees of US Citizens may be eligible to apply for a K-1 visa (US fiance visa). Furthermore, those married to Americans sometimes seek a US K-3 visa. K-1 visas and K-3 visas are generally adjudicated by an Immigrant visa unit, notwithstanding the fact that they are non-immigrant visa categories as they are treated as immigrant visas since the applicants have immigrant intent.

For related information please see: US Immigration Asia.