Norfolk Island is a territory between* Australia and New Zealand. Up until 2016 it was self-governing, however in the middle of that year Australia changed its status, and most Australian laws now also cover the territory as well.
We have a young Norfolk friend coming to visit soon, who we told would need to get an ESTA authorization in order to enter the US on the way to us.
However, because of Norfolk Island's territory status, I felt it prudent to double-check whether ESTA would be the required document, or does the US consider Norfolk Island as somehow different to Australia (as most Norfolk Islanders do) and have other requirements?
They travel with an Australian passport, however I don't know for certain whether there aren't any limitations on this for Norfolk Islanders.
*Yes I know "between" Aussie and NZ isn't entirely accurate, but it was the easiest way to describe it