VW has indicated that the Amarok would probably never be seen in show rooms in the US, I’m sure the odd Canadian or Mexican will take their Amaroks for a drive in the US, but currently there are no plans for the Amarok to be sold there.
The reason behind this was the so-called Chicken War and the resulting Chicken Tax, from what I can find in 1963 the US put a 25% tariff on several items including light trucks. Over the years all of the tariffs were removed except the one on light trucks, the idea was to protect American Manufacturing. The article on Wikipedia indicates that Ford, one of the companies originally protected, now bring in vehicles from Turkey as “Passenger Vehicles” and strip them before selling them in the US.
The result of this is that American prices would be 25% higher and that would result in the Amarok being priced out of the market. However I think it would be good if the Amarok was sold in the US because then it would be easier to get after market items.