The United States on Wednesday accused China of illegally subsidizing the production of wind power equipment and asked for talks at the World Trade Organization, the first step in filing a trade case "Import substitution subsidies are particularly harmful and inherently trade distorting, which is why they are expressly prohibited under WTO rules," Reuters quoted U.S. Trade Representative Ron Kirk as saying in a statement. "These subsidies effectively operate as a barrier to U.S. exports to China. USTR made the announcement in response to a petition filed in September by the United Steelworkers (USW). It comes about a month before a visit by Chinese President Hu Jintao to Washington for talks with President Barack Obama.