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May I apply for a US visa when I’m just visiting Japan?
Applicants for visas to the United States should generally apply at the American Embassy or Consulate with jurisdiction over their place of permanent residence. Non-immigrant visa applicants who are resident in Japan must demonstrate compelling social, economic, and professional ties to Japan in order to qualify for most visas to the US. Temporary visitors to Japan may apply for a visa, but it is more difficult to qualify for a visa outside the country of permanent residence.