If you are organizing an international physics meeting in the United States, you will need to plan ahead to ensure the attendance of international participants. Non-US citizens need to apply for their visas at least three to four months in advance. Thus, organizers should send invitation letters to these participants as early as possible.
Register Meetings with the U.S. Department of State
The International Visitors Office (IVO) encourages conference organizers to register their meeting online.
Provide Personalized Letters of Invitation
Applicants may submit a letter of invitation when applying for a visa.
IUPAP-Sponsored Meetings
For meetings sponsored by the International Union of Pure and Applied Physics (IUPAP), organizers must:
APS Commitment to Free Circulation and Travel of Scientists
The APS statement on Free Circulation at IUPAP-Sponsored Meetings (APS Statement 92.2b) advises organizers of all international meetings held in the United States to conduct their meetings in accordance with IUPAP-ICSU guidelines. Organizers are encouraged to include a statement to this effect in their meeting announcements.
The most common visa-related problem is running out of time. Encourage your attendees to begin the process early!