The legal brief the United States filed with the World Trade Organization on Thursday to oppose the designation of China as a market economy risks derailing Sino-US economic relations and reflects Washington's unwillingness to respect free trade and globalization.

The US' move, as a third party in a case China has brought against the European Union, will help it impose anti-dumping duties on imported Chinese products, which could cause losses worth billions of dollars to Chinese enterprises.

On Tuesday, the US Department of Commerce initiated anti-dumping and anti-subsidy duty investigations into Chinese aluminum products without requests by US companies, which is rare.