Fiancées of United States citizens are entitled to special nonimmigrant visas called K-1s or Fiancée Visas. Eligibility:  The alien must be coming to the United States to marry a US citizen fiancé within 90 days of entry into the United States in K-1 status. If the marriage does not occur within 90 days the alien must leave the United States. To be eligible for this visa, the couple must have physically seen each other at least once in the last two years. Upon the marriage to the US citizen, the alien must file the petition to adjust status to permanent resident with the local INS office. Documentary Requirements: Birth certificate or naturalization certificate of US citizen Divorce certificates of US citizen and/or alien, if applicable Evidence that you have seen each other at least once in the last two years. This evidence can include photos, plane tickets, entry/exit stamps in passport, etc. K-3 visas : K-3 /K-4 visas are issued to spouses and accompanying children (under age 21) of US Citizens who are the beneficiaries of an immigrant petition that is pending with the INS. The spouse and minor children can enter the US and wait for the approval of the immigrant petition of the availability of an immigrant visa.