Originally Posted by
Dread Pirate Jeff
Context: As a US citizen, is a work visa necessary all the time in Canada? I mean, if I fly into CA for a day of meetings, is a Visa necessary for that? (With the caveat that YMMV for other countries).
Though really my use case is more: Returning from Asia, via Canada (YVR or YYZ) with a long (18+ hour) layover, I'd want to not spend that long layover in the airport.
Not all the time. You would have to check applicable trade agreements such as NAFTA. But if you claim you are visa exempt due to NAFTA, CBSA may ask for documentary evidence associated with the work permit exemption criteria such as contract/RFP/invite from Canadian business etc.