For international attendees, this section features your Letter of Invitation, VISA application form, and links to locate your U.S. Embassy. If you are an international visitor, be reminded that the United States government has instituted new, tighter visa requirements for non-immigrant applicants. This may lengthen the amount of time it takes to process your VISA application. As a result, get an early jump on your visa application process by obtaining all the necessary documentation. There are several things you must do in advance to prepare for your trip to the United States.