U.S. citizens wishing to travel to Ukraine must have a valid passport with at least six months of validity beyond their planned date of travel. If the length of stay is less than 90 days, a visa is not required. Anyone traveling to Ukraine for reasons other than leisure, business or private travel must apply for a visa, regardless of his length of stay. U.S. citizens are required to present a valid, unexpired passport for entry or re-entry into the United States.
There are a number of steps that can be taken provided a six-month validity period is impossible. The first step is to look into renewal. Typical processing time is six weeks. However, an applicant can apply for an expedited passport. This has a turn-around time of about two weeks. Provided neither option is available, you can try to contact the Ukrainian embassy or consulate to obtain a special visa for travel during the expiration period.
U.S. citizens can apply for a visa through Ukrainian embassies and consulates overseas. They can also obtain one from the Consular Office of the Embassy of Ukraine in Washington, D.C., or from Ukrainian consulates general in New York, Chicago or San Francisco. Contact information for Ukrainian embassies and consulates are available on the Ukrainian Ministry of Foreign Affairs website. Visa applications should be mailed no less than three weeks before you plan to travel. For additional fees, an expedited visa application can be processed in about four days. Please note that you cannot obtain a visa once in Ukraine. Without it, you be deported.
The Ukraine visa application requires the following documents be mailed to the embassy or consulate: a valid passport (original not photocopy); the application written in block letters in black ink; a self-addressed, prepaid express envelope; a recent passport-size color photograph; a money order for the application fee and another for the visa fee; and, provided you are not a citizen of the U.S., E.U., Canada, or Japan, a letter of invitation. For a tourist visa, a letter of invitation can be obtained from a travel agency that is registered in Ukraine.
It is possible to extend your visa in Ukraine, but it must be done within four to five business days at the city OVIR (office of visas and registrations). It is important that the extension be applied for no sooner than four to five days before the visa expires. Also note that you cannot change your visa category. You also cannot make multiple entries into the country during your visa extension period. If you have a multi-entry visa and extend it in Ukraine, you can only exit Ukraine once more. When you leave, the visa is void. It is important to remember that you can't get a new visa while in Ukraine, but instead can only extend your current one. To get a new visa you must leave Ukraine and visit the consulate in a foreign country.