You want to get where you're going and you want to get back so remember that international passengers must hold a valid passport (in addition to any other required documentation) to enter or depart the United States. If you don't have your valid travel documents for the destination country and/or transit points, you won't be able to travel.
Remember To Comply With Regulations
To help your trip go smoothly, remember.
Give us the information exactly as it appears on your passport so that you're not denied boarding or refused entry into a country by border control authorities.
Check with the consulate of every country you are entering, even if you're just transiting, to make sure you are adhering to all laws, regulations, orders, demands or travel requirements.
You will be responsible for any costs, including monetary costs, resulting from noncompliance. In legal terms, the carrier shall not be liable for any aid or information given by any agent or employee of carrier to any passenger in connection with obtaining necessary documents or complying with such laws, regulations, orders, demands, requirements, or instructions, whether given orally, in writing, or otherwise, or for the consequences to any passenger resulting from his failure to obtain such documents or to comply with such laws, regulations, orders, demands, requirements or instructions. In addition, carrier reserves the right to hold, photocopy or otherwise image reproduce a travel document presented by any passenger and accepted by the carrier as a condition of boarding.
If you're a U.S. citizen, you may use an established form of identification to board flights and for entry when traveling between the United States, Puerto Rico, the U.S. Virgin Islands, Guam, the Northern Mariana Islands and American Samoa. Additional information is available from the U.S. Department of Homeland Security.
Enhanced security measures at select overseas airports
The TSA has implemented enhanced security measures at select European airports with direct flights to the U.S. If you intend to carry on electronic devices, including mobile phones, you may be required to turn them on during security screening. Devices that do not power on may not be permitted onboard the aircraft. Learn more on the TSA website.