Oceania (UK /ˌoʊʃᵻˈɑːniə, ˌoʊsᵻ-/ or US /ˌoʊʃiːˈæniə/), also known as Oceanica, is a region centred on the islands of the tropical Pacific Ocean. Opinions of what constitutes Oceania range from its three subregions of Melanesia, Micronesia, and Polynesia to, more broadly, the entire insular region between Southeast Asia and the Americas, including Australasia and the Malay Archipelago.