This is such a bogus argument.
The American territories are connected to the USA. Much the same as Canadian territories to Canada. Their is very little difference between the two definitions except American territories cannot vote in federal elections.
So I guess, Alaska and Hawaii are extra-stately dependencies that are not part of the American territory(mainland)?
And what about the Arizona Territory? (I'm quoting below an American poster in another forum)
The US has added to its territory through purchases, wars, negotiations, and outright confiscation of territory. The territories that comprise the 48 contiguous states today were not completely assimilated until 1912, when the Arizona Territory became the 48th state to be admitted to the union.
IIRC, it takes 60,000 votes to apply for statehood, and without special allowances from Congress (as in D.C.), people in territories are citizens but they cannot vote in federal elections which pivot on statehood and provisions of the US Constitution. They can vote in local and territorial elections.