Fiance Visa for US is also known as the K1 Visa. It is an immigrant visa for the United States granted to the fiancé or fiancée of the US citizen. This allows the fiancé or fiancée to marry the US citizen within 90 days of entering the country. It is the first-ever visa that a foreign national who is marrying a US citizen is required to adjust that status for becoming LPR or Legal Permanent Resident.