As of August 1, 2003, all U.S. consulate offices must interview all nonimmigrant visa applicants with few exceptions. While many consulate offices already follow this policy, this is a departure for many consulates located in Europe, Japan and a few other countries where "mail-in" or "drop box" systems were the norm.
Now a consular officer must interview each visa applicant unless it is determined tha tthe applicant presents no "national security concern" and the applicant is:
1. A child 16 years of age or younger;
2. An adult 60 years of age or older;
3. An applicant for a diplomatic or official visa;
4. An applicant for A, C, G, or NATO visa;
5. An applicant who applies for re-issue of his or her current visa within twelve month's of expiration
6. An appilcant for whom a waiver of personal appearance is in the national interest or because of unusual circumstance.

Because of this personal interview requirement, many consular posts will experience 2-3 months backlogs in appointment. Because of security issues, many posts already experience these backlogs. If you are planning to obtain a visa in your home country, plan ahead by requesting an appointment months in advance if possible. ALternatively, those who qualify may want to consider applying for a visa at a border post in Mexico or Canada where visas are often issued the same day.