Beijing has criticised new European tariffs on Chinese steel as "unjustifiable" protectionism, weeks after commerce ministers from G20 nations pledged to promote free trade.
The European Union said on Friday it had set definitive anti-dumping duties on certain Chinese steel bars at rates higher than initially proposed, following an investigation prompted by complaints from European steel-making association Eurofer.
The announcement drew an immediate response from the Chinese Ministry of Commerce, which said the EU "unfairly" set new tariffs based on higher profit targets for European producers.
Trade disputes over steel have been a point of contention in G20 talks hosted this year by China.
European producers have blamed Chinese subsidies and dumping for plunging steel prices. China has denied the accusations and said it is working to cut capacity.
Fears of a bubbling trade war over steel have dominated G20 talks hosted this year. China, the world's largest producer and consumer of steel, is looking to host a smooth summit next month in the eastern city of Hangzhou.
In G20 public communiques issued this year, member nations have sought to appear unified, pledging to work together to cut steelmaking capacity at a time when prices are at 10-year lows and struggling mills are closing from Wales to China's Hebei province.
Prices have plummeted in recent quarters as China's decades-long construction boom cools.
But tensions remain high as European Union member states and steel producers accuse China of issuing unfair subsidies and flooding global markets at below-market prices.
Beijing, meanwhile, has denied the accusations and said it is working to cut capacity even though the central government's efforts to pare down enormous state-owned steel-makers have met some political obstacles.
In a statement, the commerce ministry said it "regretted" Europe's protectionist move after a recently concluded G20 trade ministers' meeting in Shanghai and called on Brussels to "uphold its commitments and avoid sending the wrong signal to the world".
China, the EU's second largest trading partner, has been seeking "market economy status" from Brussels, which would make it harder for the bloc to impose new anti-dumping tariffs.
EU Commission president Jean-Claude Juncker said in July at the EU-China Summit in Beijing that he would vigorously defend Europe's steel industry. He added that the controversy over Chinese steel exports would shape how whether or not Brussels would give it the market economy designation.