In a sign that the trade war between the U.S. and China is heating up, the U.S. Department of Commerce has launched an anti-dumping investigation into imports of Chinese aluminum alloy sheets. It was the first countervailing and anti-dumping investigation initiated not in response to an industry complaint but “self-initiated” by the Commerce Department since 1991, when it initiated a countervailing duty probe into imports of Canadian softwood timber. “President Trump made it clear from day one that unfair trade practices will not be tolerated under this administration,” U.S. Secretary of Commerce Wilbur Ross said. “We are self-initiating the first trade case in over a quarter century, showing once again that we stand in constant vigilance in support of free, fair, and reciprocal trade.”

China’s Ministry of Commerce (MOFCOM) said the move would damage the trade in aluminum products between China and the United States, and hurt both nations’ economic interests. The Ministry said it would take “necessary action” to protect the legitimate interests of Chinese companies. U.S. imports of Chinese aluminum alloy sheet are small business – roughly just USD600 million last year – but analysts said the decision to go ahead with the investigations pointed to tougher trade confrontations down the track. “It is a clear political declaration of U.S. trade protectionism,” Sun Lei, a Beijing-based lawyer with global law firm Dentons, said. Huo Jianguo, a former research head with China’s Ministry of Commerce, said China should prepare for a long road ahead because the U.S. would not reduce its pressure on China on trade issues, the South China Morning Post reports.