China has cut tariffs on $75bn (£57.5bn) worth of imports from the US.
The move comes as trade tensions ease and Beijing tries to cushion the economic shock caused by the coronavirus outbreak.
Asian stock markets surged higher on the announcement, which follows a similar reduction by the Trump administration last month.
Markets in Europe also enjoyed a positive opening while, in New York, the Dow Jones Industrial Average and S&P 500 were trading at fresh record highs in response to the measure.
The tariffs – targeting American goods such as car parts – were imposed last September as part of the dispute between the world’s two biggest economies.
The tit-for-tat measures came after the two sides fell out over China’s trade surplus, and allegations that it was stealing technology from foreign companies.
After a year and a half of wrangling, the two sides signed a “phase one” trade deal last month, with Washington cancelling planned additional tariff hikes and Beijing committing to buy more US farm exports.
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Most of the tariff hikes imposed by both sides during the dispute, affecting billions of dollars of goods, remain in place.
Now, China is coming under additional pressure from the coronavirus outbreak that has closed factories, stores and other businesses.
It has already sought to calm financial markets by injecting 1.2tn yuan (£130bn) into the system and analysts also see the timing of the latest tariff move as a bid to boost confidence.
The announcement will see two sets of tariffs cut by half, from 15% to 7.5%, and from 10% to 5%.
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A statement from China’s Ministry of Finance said: “The next steps depend on the development of the Chinese-US economic and trade situation.
“We hope to work with the United States towards the elimination of all tariff increases.”
The tariff move added to hopes that the global economy may be able to avoid a major shock from China’s rapidly spreading coronavirus, which has battered financial markets in recent weeks.
Hong Kong’s Hang Seng index and Japan’s Nikkei climbed more than 2%, while China’s Shanghai composite added 1.7%.