Australasia

Australia's concept of Australasia, which includes Australia, New Zealand and, in this case, Melanesia

Australasia is a subregion of Oceania, comprising Australia, New Zealand (overlapping with Polynesia), and sometimes including New Guinea and surrounding islands (overlapping with Melanesia). The term is used in a number of different contexts, including geopolitically, physiogeographically, philologically, and ecologically, where the term covers several slightly different but related regions.