China expressed "deep concern" Saturday after the US launched a probe into Chinese wind towers that it suspects of being unduly subsidised and sold at a loss on the American market.

"The act will not only hamper bilateral cooperation in the field of new energy and harm the interests of US industries, but also go against global efforts to tackle the challenges of climate change and energy security," China's Ministry of Commerce said on its website.

"China expresses its deep concern over the case", it added.

The US Department of Commerce announced on Thursday that it had opened an inquiry on wind towers made in China and Vietnam, following a complaint filed by an association of four US manufacturers.

"China hopes the US side can respect relevant laws and facts, and abide by the commitment made at the G20 summit in Cannes that all countries should avoid introducing new trade protectionism measures," it said.

A wind tower is the structure that supports the engine and blades used to generate wind energy, and the tower captures that energy.

If the probe reveals the towers have been sold at a loss, the US could take out anti-dumping measures, conforming to the rules set down by the World Trade Organisation.