Why doesn't Fairphone work on 4G in the USA?

Hi I am interested in buying a Fairphone 2 when it is ready in the USA, but I read it is not compatible on 4G or 4G LTE in the USA (although it is in Europe). Can anyone explain why this is so and possible solutions to fix this? For example, would it be up to the carrier (AT&T, Verizon, etc.) to enable this or could Fairphone fix this with the way they assemble the device?

A post was merged into an existing topic: Taking Fairphone 2 to USA