What are K-3 or K-4 visas?
A K-3 visa is a nonimmigrant visa that permits the spouse of a U.S. citizen to be admitted into the United States. A K-4 visa is a nonimmigrant visa for the minor children of the K-3 spouse. Visas are issued following approval of an immediate relative petition (Form I-130). Aliens admitted to the United States on K-3 and K-4 visas may reside in the United States while waiting for the immigrant visa petition to be adjudicated and the availability of an immigrant visa.