Applying for a Visa Outside your Home Country
Immigration regulations require that "an alien applying for a nonimmigrant visa shall make application at a consular office having jurisdiction over the alien's place of residence" [22 CFR § 41.101(a)(1)]. However, regulations also allow visa applications at any other US Consulate where the applicant is physically present and which accepts applications from "Third Country Nationals".
Many US Consulates will accept these types of nonimmigrant visa applications. However, it is more difficult for a consular official outside your home country to evaluate your application, particularly ties to a residence abroad and nonimmigrant intent. Do not attempt this type of application without first speaking to an ISO Advisor to evaluate your risk.