19 CFR §122.33

1. (a)The first landing of an aircraft entering the United States from a foreign area will be:
   1. (1)At a designated international airport (see § 122.13), provided that permission to land has not been denied pursuant to § 122.12(c);
   2. (2)At a landing rights airport if permission to land has been granted (see § 122.14); or
   3. (3)At a designated user fee airport if permission to land has been granted (see § 122.15).
2. (b)Permission to land at a landing rights airport or user fee airport is not required for an emergency or forced landing (see § 122.35).