King Charles III was officially proclaimed the monarch of Australia during a ceremony held on Sunday in Canberra.
Governor-General David Hurley made the announcement in a parliamentary session.
Meanwhile, Prime Minister Anthony Albanese declared that it is not the moment for the country to return to the republic.
"My point of view on this issue is known and documented. But this is not the time to talk about our government system. Now is the time to pay our respects to the life of Queen Elizabeth. Today is also the day of the proclamation of King Charles III as Australia's head of state. This is the governing system we have, a system that as prime minister I have the duty to respect", he said.
The King of Britain was also proclaimed the monarch of New Zealand, in a ceremony held in Wellington.
Prime Minister Jacinda Ardern honored the legacy left by Queen Elizabeth II and praised the strong connection her son has with New Zealand.