Australia, officially the Commonwealth of Australia, is a sovereign country comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands. It is the largest country in Oceania and the world's sixth-largest country by total area. The population of 26 million is highly urbanised and heavily concentrated on the eastern seaboard.

China, officially the People's Republic of China, is a country in East Asia. It is the world's most populous country, with a population of around 1.4 billion in 2019. Covering approximately 9.6 million square kilometers (3.7 million mi2), it is the world's third or fourth-largest country by area. China extends across much of East Asia, bordering Vietnam, Laos, and Myanmar (Burma) in Southeast Asia; India, Bhutan, Nepal, Afghanistan, and Pakistan in South Asia; Tajikistan, Kyrgyzstan and Kazakhstan in Central Asia; and Russia, Mongolia, and North Korea in Inner Asia and Northeast Asia.