I am intend to visit the United States from the United Kingdom for about 80 days under the Visa Waiver Program (I already have an ESTA approved). After this, I intend to fly to Canada to stay for 3-4 months and then return to the UK. I figured that proof of my intent to leave the United States before the 90 days granted by the VWP, and a further ticket from Canada to the UK would be sufficient proof of intent (as well as supporting documents like mortgage statements, bank statements, etc).
However, when going through the steps to book a flight through Kiwi.com, I found the following statement:
A return/onward ticket (or electronic ticket record) must be to a final destination country other than Canada, Mexico or contiguous (adjacent) countries or territories situated in or bordering the Caribbean Sea . If passenger holds proof of residence in, or is transiting the USA to such a country or territory, an onward/return ticket to that country or territory is accepted. Passenger can make side trips to Canada, Mexico or Caribbean countries/islands, provided first entering the USA on a carrier participating in the VWP. No additional time is given (extension) based on the departure to contiguous (adjacent) territory .
Does this mean I would be required to provide proof of intent to leave the US for the United Kingdom within the 90 days granted by the VWP? Would my ticket from Canada to the UK several months after those 90 days have passed be sufficient evidence to prove my intent to not overstay in the United States? I've read a fair amount on the DoS website, etc. but this is the first time I have read a statement like this.