Any student who is traveling outside the United States whose U.S. visa has expired will need to renew it at an U.S. visa issuing post abroad before the student can return to the United States. In most cases, the visa application will be filed in your home country. Its important to note that the summer period is an extremely busy time at visa issuing posts due to large numbers of travelers and reduced staff who may be taking vacation. Also, in the event of any protests, threats, or terrorist attacks that are judged to be threatening to U.S. embassy or consulate personnel, government officials at those posts may temporarily close or alter their operational hours. It is advisable to check with the U.S. consulate or embassy, or its web site link: http://travel.state.gov for the most current information, although keep in mind that information on the web site might not necessarily be up-to-date. Some visa issuing posts have stopped accepting non-immigrant visa applications filed in person, and will only accept them by mail or through an approved "drop-off" facility. Drop off or mailed visa applications will always add to the processing time.