There is not much for B visa and they will want you have strong ties in resident country and have enough money to take care of expenses while in US.
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They have this list in the email which will confirm after submitting appointment/scheduled for dropbox. But as usual no list is finite. They can email you and ask for more.
The following documents are required for all visa types:
- Current Passport valid for travel to the United States. The passport must be valid for at least six months beyond the period of stay in the United States (unless exempt by country-specific agreements.)
- Passport containing the most recently issued U.S. visa (if applicable).
- Nonimmigrant Visa Application, Form DS-160 confirmation page.
- Confirmation and Instructions page printed from this website
- One 5 x 5 cm (2 x 2 inches) color photo taken within the last 6 months. Further details regarding Department of State photo guidelines can be found at: https://travel.state.gov/content/travel/en/us-visas/visa-information-resources/photos.html.
- Accompanying family members, unless entering the United States for another purpose, should present a marriage certificate (spouse) and/or birth certificate (for unmarried children under 21), as applicable.
- Copy of proof of your legal status in Canada
If you are attending an appointment in person, you must bring original documents. If you are eligible to send your documents via courier, you must send your current valid passport and the prior passport containing the most recently issued U.S visa (if applicable), as well as the DS-160 confirmation page and copies of any other supporting documents. Please see the section below for a list of supporting documents required for each visa type.
(H) TEMPORARY WORKER
- Receipt Number for your approved petition as it appears on your Petition for a Nonimmigrant Worker Form I-129 or Notice of Action Form I-797 from USCIS (does not apply to H1B1 visa applicants).
- Job offer from United States employer and a Certified Department of Labor approved application (applies to H1B1 visa applicants only).