Contact the closest U.S. Embassy or Consulate and ask to talk with someone in the American Citizens Services department of the Consular Section regarding the lost passport. Advise your contact of all your travel dates and departure times.
Take a new set of passport photos locally, if you do not already have an extra set with you.
Fill out a new passport application and be prepared to answer any questions that the consulate employees ask regarding your citizenship and travel itinerary.
Provide the U.S. Embassy with a photocopy of your passport if you have one along with your personal information, such as your name, birthday and place of birth. Give copies of any identification you may have with you, such as a drivers license. Fill out an affidavit or give a sworn statement explaining how your passport was lost or stolen.
Pay the passport replacement application fee. Ask family members or friends to send money if you can not pay the full amount, or else the Embassy can issue a limited validity passport that will expire upon your return to the United States.