K-1 classification is for noncitizens who seek to enter the United States to marry a U.S. citizen. Prerequisite to the issuance of a K-1 nonimmigrant visa is the approval of a visa petition (I-129F) submitted by the U.S. citizen. Such a petition can be approved only if the petitioner presents satisfactory evidence that the parties: 1)previously met in person within two years before filing the petition, although this requirement of personal meeting may be waived by the USCIS;2) have a bona fide intention to marry; and 3) are legally able and willing to conclude a valid marriage in the United States within ninety days after the noncitizen's arrival. Children of such noncitizensn can apply for K-2 visas.