The movement of any goods outside of the United States is considered an export and must be done so in compliance with U.S. export laws. This includes goods that you carry out of the United States in the course of international travel.
All military goods (including those produced through DARPA funding) and items qualified for operation in outer space will require a license to be exported. While most commercial goods do not require a license to be exported, various commercial items are controlled to certain destinations such as: Afghanistan, Belarus, Burma (Myanmar), China, Congo, Cyprus, Eritrea, Fiji, Haiti, Iraq, Ivory Coast, Lebanon, Liberia, Libya, Palestinian Authority / Hamas, Somalia, Sri Lanka, Vietnam, Venezuela, Yemen, and Zimbabwe.
Any export to one the following embargoed countries must be reviewed by the Office of Export Controls well in advance as it will likely require a license (regardless of commodity):
- North Korea
Exports valued at more than $2,500.00 must be reported to the US government through an EEI (Electronic Export Information) submission, formerly known as Shipper's Export Declaration (SED), regardless of whether or not a license is required.
Export laws require that all shipping documents (Customs Invoices, Packing Lists, Export Licenses, Purchase Orders, emails, etc.) be kept for a minimum of five years from the time of export.
See here for further info on license applications and EEI filings.