The US Commerce Department issued a statement Tuesday announcing “historic antidumping and countervailing duty investigations” into Chinese aluminum, prompting a swift response from Beijing.

China is “strongly dissatisfied” with the investigation, the Ministry of Commerce said in a statement Wednesday, as reported by Caixin.

“The two countries’ aluminum industries are reciprocally complementary,” Wang Maojun, director of the ministry’s trade remedy bureau was quoted as saying in the statement.

The US announcement quoted Secretary Ross, who cited Trump’s commitment to confronting trade issues.

“President Trump made it clear from day one that unfair trade practices will not be tolerated under this administration, and today we take one more step in fulfilling that promise,” said Secretary Ross. “We are self-initiating the first trade case in over a quarter century, showing once again that we stand in constant vigilance in support of free, fair, and reciprocal trade.”

Final determinations in the cases are scheduled for April 2018 for the countervailing duty investigation, and July 2018 for the antidumping duty investigation, though they could be subject to extension. The Commerce Department already imposed preliminary import duties on aluminum foil from China in late October.

Though the ongoing investigations mark a step towards Trump following through on his confrontational trade rhetoric, fallout from any further action in this area alone would be minimal. US aluminum imports from China in 2016 were valued at just US$603.6 million, according to the Commerce Department.