An American citizen planning on marrying a foreigner has the option of bringing his or her fiancé(e) to the United States on a temporary non-immigrant visa to marry and live in the U.S. through the K-1 visa. The American citizen may also apply to bring his or her fiancé(e)'s unmarried children, who are under the age of 21, to the United States via the same visa petition.
Legal permanent residents (green card holders) may not file petitions for the fiancé(e) visas, although they may petition for the immigration of their new spouse after the wedding.
The K-1 visa is a temporary visa to the United States for the sole purpose of getting married within the United States. This visa is not a permission to stay in the U.S. for long term. The applicant has 90 days to get married after the alien fiancé(e) arrives in the U.S.. If he/she plans to stay/work in the U.S. the alien spouse will have to file another petition and application in order to adjust his/her status to a permanent resident (green card holder).
Until the marriage takes place, the alien fiancé(e) is considered a non-immigrant. The alien fiancé(e) may enter the United States only one time with a fiancé(e) visa. If the alien fiancé(e) leaves the country before they are married, the alien fiancé(e) may not be allowed back into the United States without a new visa. If the marriage does not take place within 90 days or the alien fiancé(e) marries someone other than the U.S. citizen filing the petition, the alien fiancé(e) will be required to leave the United States.
If the alien fiancé(e) intends to live and work permanently in the United States, he or she must apply to become a permanent resident after the marriage. If the alien fiancé(e) does not intend to become a permanent resident after the marriage, the alien fiancé(e)/new spouse must leave the country within the 90-day original non-immigrant admission.