I used the NIV deliberately to show the difference in translations. The NAS use "repent". I don't have time to go into a great deal of detail (I must run) but they are one in the same. The term repent is poorly translated. The NIV accurately translate the Hebrew word that God does not change His mind.
I think "repent" is a better translation of the Hebrew text than "change his mind". Especially when the rest of the verse is taken in the context.