Most foreign nationals must obtain a visa at a U.S. Consulate or Embassy in their home country before coming to the U.S. to study or work.
At your visa interview, the U.S. Consular Officer will review your supporting documents and choose to approve or deny your application. Non-immigrants applying for a non-immigrant visa must show proof of adequate financial resources, provide evidence of close ties to the home country, and convince the Consular Officer that he/she has no intention of remaining in the U.S. permanently.
Visas are used to gain entry to the U.S. in a particular immigration status. They are issued for varying lengths of stay and may be for single or multiple entries. The visa stamp is placed in the foreign passport.
A visa is an entry document only; it does not indicate how long a foreign national is permitted to stay in the U.S. The length of stay is determined by an Immigration Officer at the port of entry and the date is specified on the Form I-94, Record of Arrival and Departure. It is the I-94 record, combined with other immigration documents, which authorize the length of time a foreign national is permitted to remain in the U.S.
If the non-immigrant visa expires after the foreign national is lawfully admitted to the U.S., it is permissible for him/her to remain in the U.S. as long as the I-94 record and other immigration documents remain valid. However, as soon as the foreign national departs the U.S., a new visa is required to re-enter.
NOTE: In most cases, international students will need to apply for an F-1 visa. Others may need to apply for J-1 (exchange visitor) visa. Click Here for more information.