Citizens of certain countries can travel to the US on the visa waiver program, without obtaining a visa in advance, if they meet all the requirements. Travelers must have a valid Electronic System for Travel Authorization (ESTA) approval prior to travel. For more information, please visit the official government website.
Participants who are not eligible for this program should apply for a B1 visa. For more information, please check here. An official invitation letter can be provided upon request. Please send an email to etuzel [at] dpi [dot] edu for such injuries.