U.S. President Barack Obama warned China Tuesday that it will not be allowed to gain an unfair advantage in world trade by "skirting the rules." President Obama announced in remarks made at the White House that the United States was bringing a new trade case against Beijing to pressure China to end its restrictions on exports of materials known as rare earth, which are used to manufacture hybrid car batteries, flat screen televisions, and other high-tech goods. "If China would simply let the market work on its own, we would have no objection," President Obama said. "But their policies currently are preventing that from happening. And they go against the very rules that China agreed to follow." The United States, the European Union, and Japan asked the World Trade Organization (WTO) Tuesday to facilitate talks with China over its curtailment of exports of rare earth minerals.