The shortage of HT drivers seems to be an international phenomenon. NZ has a highly effective moat to prevent illegal migration, so the market will be forced to do its duty and authorize skilled migrant categories or incentivise training or raise wages until demand is met. If the US had a moat or wall, the market would be forced to do the same rather than encouraging illegal immigration that depresses wages and consumes jobs that citizens might like.
"... They ne'er cared for us
yet: suffer us to famish, and their store-houses
crammed with grain; make edicts for usury, to
support usurers; repeal daily any wholesome act
established against the rich, and provide more
piercing statutes daily, to chain up and restrain
the poor. If the wars eat us not up, they will; and
there's all the love they bear us."
-- Shakespeare: Coriolanus, Act 1, scene 1