Visitors to the Canada must have a valid passport. Delegates to the Conference qualify as business visitors to Canada. Firstly, one should find out if one needs a visa to enter Canada.
Electronic Travel Authorization (ETA)
Visa exemptions are provided to citizens of many countries and territories such as Australia, Britain, France, Germany, Korea, Singapore, Switzerland, Taiwan, United States, etc. Starting March 15, 2016, visa-exempt foreign nationals except citizens of United States who fly to or transit through Canada will need an Electronic Travel Authorization (ETA).
More details about eTA can be found here - http://www.cic.gc.ca/english/visit/eta.asp.
How to Obtain a Visa
citizens of a few other countries such as China, India, Philippines, South Africa, etc require a visa to enter Canada.
Attendees of a scientific conference should apply for a business visitor visa to Canada.
Request for Visa Support Letter
For security purposes, the conference has policy for issuing official Visa Support Letters as follows:
Visa Support Letters will be issued via email in PDF format. Please contact the Conference Manager at [email protected] to arrange for a Visa Support Letter. You must include:
Note: Obtaining a Visa Support Letter will not guarantee that your visa application will be approved. The letter is merely supplementary information that explains a visa applicant's intended purpose of travel to Canada.
Please note that this information is given in good faith but that the regulations may change and the only authoritative sources of information are the U.S. Government websites.