The latest round in the trade war between the US and China is underway.
The two countries put into effect 25 percent tariffs on $16 billion worth of each other's goods.
That makes it $50 billion worth of imports subjected to tariffs on either side since early July, and more are in the pipeline, adding to risks for global economic growth.
China's Commerce Ministry said Washington was "remaining obstinate" by implementing the latest tariffs, according to Reuters.
The next round could see a list of an additional $200 billion worth of Chinese imports face duties.
The tariffs took effect while US and Chinese officials hold two days of talks in Washington.
President Trump has threatened to impose duties on virtually all of the more than $500 billion of Chinese goods exported annually to the United States unless Beijing agrees to sweeping changes to its intellectual property practices, industrial subsidy programs and tariff structures and buys more U.S. goods.
Washington's latest tariffs apply to products including semiconductors, plastics, chemicals and railway equipment that the Office of the U.S. Trade Representative has said benefit from Beijing's "Made in China 2025" industrial plan to make China competitive in high-tech industries.
China's list of 333 U.S. product categories hit with duties includes coal, copper scrap, fuel, steel products, buses and medical equipment.