The White House clarified that Chinese imports will be tariffed at 145%, not the 125% rate that US President Donald Trump's had written about in his posting on Truth Social.
The 125% did not include a pre-existing tariff of 20% from earlier in the year over China's alleged role in the fentanyl supply chain.
This takes the total tariffs Trump has imposed on Chinese products this year to 145%.
Wall Street reacted immediately with the S&P 500 losing 5%, more than half its prior gain.
Before the announcement China has said it will "fight to the end" if no compromise is reached.
On Wednesday, Trump abruptly reversed course as he announced a 90-day pause on tariffs for all countries except China.