In Cambodia, nonimmigrant visa interviews are conducted by appointment only from Monday to Thursday. Each visa applicant will have to make an individual appointment even if they are minors. After you have completed the application form, DS-160, please print out the confirmation page that contains some biometric information with the barcode (see sample here - JPG: 76 KB) to bring to your visa interview. Then click here to schedule an online appointment for a visa interview. Do not forget to print out an appointment confirmation letter (see sample here - JPG: 92 KB) to bring to the Consular Section on the day of your appointment. Please understand that the process of U.S. visa’s application has many steps to undergo and even though, you have scheduled an online appointment which only provides you admissions into the Consular Section to submit your visa application. Please understand that the formal process of your visa application can only be started on the day you appear for the visa interview, after you paid the non-refundable visa application fee at a cashier window inside the consular section, so please be prepared to wait in the Consular Waiting Room.
You should apply for a visa at least 4-5 weeks before you intend to travel. Visa appointment wait times and processing vary, especially during peak travel seasons.
However, after scheduling an interview appointment, if you prefer an earlier appointment sooner than the one you had and the purpose of your trip to the U.S. is not for emergency and may not meet the requirements to request for emergency appointment, you should try to view this website Appointment Scheduling System regularly (select “Schedule Appointment” enter the information from your appointment confirmation letter) to see if there are any other earlier appointments available in case other applicants cancelled or rescheduled their appointments. An applicant’s failure to plan in advance is not the grounds for considering an earlier appointment and we usually cannot accommodate last minute appointment requests.
Nonimmigrant visas for Cambodian citizens are generally valid for three months, so you should apply for a visa within three months of your departure date.