Johnston Atoll is an unincorporated territory of the United States, under the jurisdiction of the United States Air Force (USAF). The island is closed to public entry, and limited access for management needs is only granted by letter of authorization from the USAF. A special use permit is also required from the United States Fish and Wildlife Service (USFWS) to access the island by boat or enter the waters surrounding the island, which are designated as a National Wildlife Refuge and part of the Pacific Remote Islands Marine National Monument. The Johnston Atoll National Wildlife Refuge extends from the shore out to 12 nautical miles, continuing as part of the National Wildlife Refuge System out to 200 nautical miles. The Pacific Remote Islands Marine National Monument extends from the shore out to 200 nautical miles.

Territories of the United States are sub-national administrative divisions overseen by the federal government of the United States. The various American territories differ from the U.S. states and Indian reservations as they are not sovereign entities. In contrast, each state has a sovereignty separate from that of the federal government and each federally recognized Native American tribe possesses limited tribal sovereignty as a "dependent sovereign nation." Territories are classified by incorporation and whether they have an "organized" government through an organic act passed by the Congress. American territories are under American sovereignty and, consequently, may be treated as part of the United States proper in some ways and not others. Unincorporated territories in particular are not considered to be integral parts of the United States, and the Constitution of the United States applies only partially in those territories.