Download Request for Visa Assistance form and send it back to the contact given in the form.

IEEE's guidelines for providing visa letters are as follows:

(Source: Visa Request Process for IEEE Conferences)

Visa letters should only be issued to

• People the committee knows
• Speakers/Presenters
• Committee members
• Attendees who have paid their registration fee in full and are not from one of the countries embargoed by the U.S. Treasury Department's Office of Foreign Assets Control

Visa letters should state only the facts

• Conference title, dates and location
• That the requester has paid the required registration fee in full (Verify that the credit card clears before providing letter).
• If they are either a committee member, speaker or presenter

Additional information can be found on the U.S. Department of State Bureau of Consular Affairs Visa Services Web Site -
  http://travel.state.gov/visa/visa_1750.html.