K-1/K-3
This visa can be issued to the fiancé (K-1) or married spouse (K-3) of a U.S. citizen. The spouse of a U.S. citizen can enter the country by applying for permanent residence at the U.S. embassy in the foreign country, but it takes a long time to obtain a visa to enter the U.S. within a short period of time. Unmarried children under the age of 21 of a foreign spouse are eligible for a K-4 visa.