The K-1 “Fiancé visa” is a nonimmigrant visa that permits a foreign national fiancé of a U.S. citizen to travel to the United States to marry the petitioning U.S. citizen sponsor within 90 days of admission to the country.
Once the couple marries, the foreign citizen can adjust her status to become a lawful permanent resident of the United States (Green Card holder). Although a K-1 visa is legally classified as a non-immigrant visa, it usually leads to important immigration benefits and is therefore often processed by the Immigrant Visa section of United States embassies and consulates worldwide. If a K-1 visa holder does not marry his or her U.S. citizen petitioner within 90 days of entry, then she must depart the United States within 30 days.
Official instructions are available from the USCIS web site, or the US Department of State web site. In order to file the petition a man has to attach certain documents and forms filled out and signed by his fiancé. Our agency helps facilitate the process of gathering, translating, and notarizing the required documents from the lady’s side and also filling out the G-325A biographical forms in English.
Once the petition is approved by the USCIS the documents are sent over to the American embassy in Kiev. Once the documents arrive in Kiev, the consulate will notify you of their arrival, so your lady can pick a date for her medical examination and interview at the embassy. The lady must first fill out the DS156 and DS156K forms, and obtain a copy of the translated and certified police certificate (this documents states that the lady has not been under criminal investigations), translated and certified birth certificate, copy of the passport, set of pictures (certain specific size) and etc. The fee for the interview is required to be paid in advance and this can be done from the US side, the fee for the medical examination has to be paid in cash. The only hospital in Ukraine which is recognized by the US embassy to run the medical examinations is located in Kiev. After the medical examination the lady gets a package with the results which she needs to bring to the embassy (normally the interview takes place the next day after the medical examination).
The link below provides information for the US Government K-1 Visa Process step-by-step: