China's commerce ministry said on Thursday it has initiated a World Trade Organization (WTO) dispute resolution procedure over US tariffs on its import of steel and aluminum.
The move follows a back and forth dispute between the two countries over free trade, that has escalated from an investigation by the United States into China's intellectual property practices to imposing tariffs on imports.
The Ministry of Commerce said the US measures against its steel and aluminum were not for maintaining national security, but rather were in aid of trade protectionism.
The ministry said in a statement posted on its website the US action were a "serious violation of the non-discrimination principle of the multilateral trading system", and violated its tariff-reduction commitments under the WTO.
After the United States failed to negotiate compensation, China had to initiate the dispute settlement procedure to defend its rights and interests, the ministry said.
The US Trade Representative’s office said earlier that the tariffs were put in place on national security grounds and objections were "baseless".
WTO rules include an exemption for measures related to national security.