A personal letter from the applicant covering personal details, the purpose of the visit, and outlining who will be responsible for the full costs of the trip. Travel, the accommodation also need to include. The letter should be addressed to The Visa Officer, U.S. Embassy, Dhaka. The Visa category must be mentioned in the subject line. The purpose of your visit to the United States is for a temporary visit, business visit, or medical treatment. Remain time in the united states specifically and evidence of founds.