Xu Xu, president of the China Chamber of Commerce of Metals, Minerals and Chemicals Imports and Exporters, said in a prepared speech that China should establish a mineral resource reserve system integrating state-owned and private company stockpiles, Bloomberg reported. "Mineral reserves should include both mineral resources and finished products," he said at an industry conference in Beijing. He said that the necessity to import minerals has become one of China’s "bottlenecks of economic development, threatening China’s economic security." Copper and iron ore imports account for 40% and 60% of domestic consumption, respectively. China has already begun hoarding rare earths, which are used in a variety of applications including alternative energy technologies.