The US has more than doubled tariffs on $200bn worth of Chinese products, in a sharp escalation of the countries' damaging trade war.
Tariffs on affected Chinese goods have risen to 25% from 10%, and Beijing has vowed to retaliate.
China says it "deeply regrets" the move and will have to take "necessary counter-measures."
It comes as high-level officials from both sides are attempting to salvage a trade deal in Washington.
Only recently, the US and China appeared to be close to ending months of trade tensions.
China's Commerce Ministry confirmed the latest US tariff increase on its website.
"It is hoped that the US and the Chinese sides will work together... to resolve existing problems through co-operation and consultation," it said in a statement.
Tariffs are taxes paid by importers on foreign goods, so the 25% tariff will be paid by American companies who bring Chinese goods into the country.