Except in very limited circumstances, if an alien wants to enter the United States as a non-immigrant, an alien must apply for a non-immigrant visa at a U.S. consulate or embassy abroad. Pursuant to Immigration and Naturalization law, an alien applying for a visa to enter the United States is presumed to have immigrant intent. An alien seeking to obtain a non-immigrant visa has a burden to prove that he does not have intent to immigrate. This is done by presenting to the U.S. consulate the documents required by the U.S. Citizenship and Immigrations Services (USCIS) (formerly Immigration and Naturalization Services (INS)) for the particular visa the alien is seeking to obtain. The U.S. consular officers will review an alien's visa application and decide whether the alien has satisfied his burden of proving nonimmigrant intent. In most instances, a pending application for permanent residence precludes an alien from attempting to prove the requisite nonimmigrant intent required for the particular nonimmigrant visa he is seeking to obtain. However, there are some classes of non-immigrant visas where an application for permanent residence does not bar the alien from attempting to prove the nonimmigrant intent he needs to show to obtain the nonimmigrant visa he is seeking. In these instances, the USCIS allows the alien applicant to have dual intent (i.e., the intent to immigrate and nonimmigrant intent).

The U.S. consular officials have a wide range of discretion to deny a visa application. A U.S. consular official can deny a visa application for any reason or no reason at all. Aliens who are seeking to obtain a nonimmigrant visa for entry into the U.S. make their applications by gathering together the following to present to the U.S. consulate:

1. Form DS-156, the standard nonimmigrant visa application.
2. Passport of the visa applicant.
3. One photograph following these requirements.
4. Applicable application fee.
5. USCIS approval notice of a nonimmigrant petition or certification from sponsoring institution when such prior approval or certification is required for issuance of a nonimmigrant visa.
6. Supporting documentation establishing the alien's eligibility for the particular nonimmigrant visa sought.

In most instances, the visa seeking alien submits the above to a visa issuing U.S. consulate by making a personal appearance at the consulate. After the alien physically submits the application materials, the alien waits while the papers are reviewed by a consular officer. When the initial review is complete, the consular officer will typically call the alien in for questioning. If the consular officer is satisfied with the alien's responses and visa application, the alien's application is approved. In countries where visa refusal rate is low, consulates allow the visa application to be mailed to them.

Generally, a nonimmigrant visa application can be made at any visa issuing U.S. consulate, and there is no requirement that the alien  apply for the visa in the alien's home country. However, there is one notable exception. An alien must apply for a nonimmigrant visa in his home country if the alien was issued a nonimmigrant visa in the past, was admitted to the U.S. based on that nonimmigrant visa, and remained in the U.S. beyond the period of stay authorized by that visa.

For more information on non-immigrant visa, please click on the following links:
What is a non-immigrant visa?
Who needs a non-immigrant visa?
What are some common non-immigrant visas?
What is the difference between visa and non-immigrant status?
Consulate process for non-immigrants
Entry into the United States
Visa Waiver Pilot Program (VWPP)
Attorney Fees