Originally Posted by
bocastephen
It is correct - you cannot transit the USA in any way without being admissible into the USA with a visa, visa waiver or Canadian passport. Additionally, anyone without a Canadian passport may be required to complete the ESTA process before departure. No USA airport has a sterile transit facility and all passengers arriving from any destination outside of the USA, except certain pre-clearance airports, must clear US immigration on arrival before continuing on their journey.
Yep. when ANZ transited LAX en-route to AKL from LHR, you had to enter the US even though you weren't leaving the airport and needed an ESTA. Was at LHR witnessed people being told to get an ESTA pronto or they wouldn't even get to check in.