East Asia is a region of Asia, which is defined in both geographical and ethno-cultural terms. The sovereign states of East Asia include China, Japan, Mongolia, North Korea, South Korea, and Taiwan. Hong Kong and Macau, two small coastal cities located in the south of China, are autonomous regions under Chinese sovereignty. The economies of Japan, South Korea, China, Taiwan, Hong Kong, and Macau are some of the world's largest and most prosperous economies. East Asia borders Siberia and the Russian Far East to the north, Southeast Asia to the south, South Asia to the southwest, and Central Asia to the west. To the east is the Pacific Ocean and to the southeast is Micronesia .