What is K-1 Visa?
The fiancee K-1 nonimmigrant visa is for the foreign-citizen fiancee of a United States (U.S.) citizen. The K-1 visa permits the foreign-citizen fiancee to travel to the United States and marry his or her U.S. citizen sponsor within 90 days of arrival.
An approved I-129F petition remains valid for four months from the date of USCIS’s approval. Consular officers can extend the validity of the petition (revalidate the petition), and in practice does so while the application is being processed.