Oil palms only grow in humid tropical environments. Environments that when left undisturbed would be tropical rainforest. Decoupling palm oil from deforestation is therefore very hard. Certified sustainable palmoil is simply from farmland that the farmers have proved not to have been deforested recently but that same land still has the potential to return to tropical rainforest after restoration.

Regarding America specifically probably only Hawaii could support it. But land there is scarce and is used for much higher value crops like fruit crops. Harvesting palm oil is also quite labor intensive since the fruit bunches are harvested manually. It therefore does not make economic sense to grow it in countries with high wages.