US Visa

Important Visa Information for International Travellers

International travelers who need a visa to enter the United States should apply as soon as possible. To facilitate visa application the conference organizers will, on request, supply a letter of invitation to all bona fide conference attendees that can be submitted with the visa application. You should request this letter  when registering on-line, by checking a box you will see on the registration form. Alternatively, if you want to wait for the outcome of your visa application before registering, you can send your letter request (including your full contact information and passport number) by e-mail to If you register for the meeting and your visa application is denied, the organizers will give you a full refund (waiving the normal 15% cancelation penalty).

The US State Department’s Visa Waiver Program allows visitors from 90 countries to enter the US for a stay of up to 90 days without a visa. If you are eligible for the Visa Waiver Program you still need an ESTA – Electronic System for Travel Authorization. For information on the Visa Waiver Program, including countries covered and how to apply for the ESTA, please go here. Even though you will in most cases not need an invitation letter to apply for the ESTA, the conference organizers will still upon request issue a letter which you can bring with you and have ready to show to immigration officials when you enter the US. Please request the letter by checking the appropriate box on the registration form on-line (or request by email to

The United States National Academy of Sciences (US-NAS) has set up a web site to assist all foreign conference attendees who need to apply for a visa. This web site is an important resource for scientists attending conferences in the United States. In addition to background materials the site provides important information regarding country specific visa requirements, advice regarding possible visa delays, and advice to travellers upon arrival in the United States.

The conference organizers have registered CCP2014 with the US-NAS. According to US-NAS, this means that information about CCP2014 will be shared with US Department of State Visa Services and should be available to US Consular Offices worldwide.