The rare earth export restrictions by China have been made out of consideration for the environment and the sustainable utilization of resources, rather than export protection -- that's according to Chinese officials responding to complaints made by the US, EU and Japan.

Soil containing rare earth minerals waits to be loaded at a port in Lianyungang, east China's Jiangsu province, for export to Japan in 2010.

Chinese Foreign Ministry Spokesperson Liu Weimin says China has made unremitting efforts in providing rare earth minerals to the international community.

Liu said: "China's rare earth resources account for 36.4% of the overall reserves in the world. However, China provides more than 90 percent of the global supply of rare earth minerals, and this situation is unsustainable. Therefore China has adopted some control measures. Despite the immense environmental pressures, China's has not stopped exporting rare earths."

Liu urged other countries possessing rare earth minerals to increase their resources and shoulder their due responsibilities.

Liu said: "We hope other countries holding rare earth resources can actively unlock their development of rare earths and shoulder the responsibility to provide rare earths to the international community, alongside China."

China is preparing to defend itself should the US and other countries bring the rare earth case to the World Trade Organization.

China says that supplies of some rare earth metals would run out within 20 years, if it were to increase exports, and that such a move would come at the expense of the global environment and resources.