A K-1 visa is a visa issued to the fiancé or fiancée of a United States citizen to enter the United States. A K-1 visa requires a foreigner to marry his or her U.S. citizen petitioner within 90 days of entry, or depart the United States. Once the couple marries, the foreign citizen can adjust status to become a lawful permanent resident of the United States (Green Card holder). A K-2 visa is issued to unmarried children under the age of 21. Foreign same-sex partners of United States citizens are currently recognized by United States Citizenship and Immigration Services (USCIS) and accordingly can be sponsored for K-1 visas and for permanent resident status.