In 1964, it was proposed to relocate the population of Nauru to Curtis Island off the coast of Queensland, Australia. By that time, Nauru had been extensively mined for phosphate by companies from Australia, Britain, and New Zealand, damaging the landscape so much that it was thought the island would be uninhabitable by the 1990s. Rehabilitating the island was seen as financially impossible. In 1962, Australian Prime Minister Robert Menzies said that the three countries involved in the mining had an obligation to provide a solution for the Nauruan people, and proposed finding a new island for them. In 1963, the Australian Government proposed to acquire all the land on Curtis Island (which was considerably larger than Nauru) and then offer the Nauruans freehold title over the island and that the Nauruans would become Australian citizens. The cost of resettling the Nauruans on Curtis Island was estimated to be , which included housing and infrastructure and the establishment of pastoral, agricultural, and fishing industries. However, the Nauruan people did not wish to become Australian citizens and wanted to be given sovereignty over Curtis Island to establish themselves as an independent nation, which Australia would not agree to. Nauru rejected the proposal to move to Curtis Island, instead choosing to become an independent nation operating their mines in Nauru.