"If players in the world do not stick to the rulebook the system might collapse and that is why we are challenging today both the US and China at the WTO," Malmstrom told reporters.
According to the European Commission, the case launched by the European Union targets specific Chinese provisions on export and import of technologies as well as the regulation on Chinese-foreign equity joint ventures, which "discriminate against non-Chinese companies."
These provisions violate the WTO rules that require its member states to treat foreign companies on an equal basis with domestic ones, the Commission said.
According to Malmstrom, Washington's decision to impose trade tariffs on steel and aluminum is a very unfortunate step since it is further damaging transatlantic relations.
"It is very unfortunate because it will cause a lot of damage to our steel and aluminum industry… It is pure protectionism… This is further weakening the transatlantic relations," Malmstroem said.
The commissioner stressed that Brussels tried to avoid such situation through talks and wanted mutually beneficial conditions.
"The US was not ready to engage on these premises. They tried to push us to make concessions… to limit trade and our exports on a voluntary basis. This is not the way the European Union is negotiating," Malmstroem concluded.
At the same time, the official noted that the European Union did not expect the United States to retaliate to measures that the bloc would take in response to Washington’s new tariffs on aluminum and steel.
"That they [Washington] would retaliate on our rebalancing measures on an illegal measure? No, he [Ross] did not say anything about this [during talks earlier in the week]," Malmstrom said, asked a corresponding question.
The commissioner stressed that the European Union was not in a trade war with the United States.
"We are not in a trade war, but we are in a very difficult situation caused by the United States and these tariffs that are imposed not only on us but on other big economic players in the world," Malmstrom said.
In March, US President Donald Trump signed an order to impose a 25-percent import tax on steel and 10-percent duties on aluminum. The new tariffs would be in place for an indefinite period of time, but the European Union and six other US allies, including Argentina, Australia, Brazil, Canada, Mexico and South Korea, were given a temporary exemption until May 1.