There are new requirements for all foreign passengers traveling to the US For more information, please visit the Department of State: https://bit.ly/TravelGovFAQs. For COVID-19 testing requirements, visit the CDC: https://bit.ly/InternationalTravelCDC.
The airline is the one who requests negative proof
In the United States they do not ask for it, the airline takes care of that and I think they deliver all the information to the destination airport
Thanks! Your answer is awaiting moderation.