If the person in Vietnam and is a finance, he or she will get a K-1 Visa.

The processing time for a K1 Visa will take anywhere from 3 to 6 months.  In order to get a visa, some of the things that are required include a document stating that the person is able to get married, a medical examination, evidence of a valid relationship, passport, birth certificates, divorce or death certificate of any other spouse.  Once the alien fiancée is in America he/she will have to get married with the sponsor within 90 days.

After the marriage, the alien spouse must apply to the USCIS to obtain a record for conditional permanent resident status.