[Repeal 16-17]

Doesn’t statehood have to be approved by the states, or can it be done unilaterally by Congress?

Article IV, Section 3, Clause 1 gives Congress authority to admit new States. It does not require Congress receive consent from the territory to be admitted. The only express limitations on Congress's statehood power involve the borders of already admitted States.

[Lurkina.n.Learnin]

So they can declare Canada and Mexico states?