Timing will depend on the actions of the United States, the Chinese Commerce Ministry said in a separate statement. "I noticed today that Japan's stock market is now worth more than China's - I love that", he told journalists at the White House.
"Instead of retaliating, China should address the long-standing concerns about its unfair trading practices", White House spokeswoman Sarah Sanders said in an emailed statement.
Days later, Washington unveiled a list of another $200 billion in Chinese goods, from areas as varied as electrical machinery, leather goods and seafood, that would be hit with 10 percent import duties.
The move comes after Trump asked United States trade officials to consider imposing a 25% tariff on $200bn of Chinese goods, up from the 10% level originally proposed last month, as the two countries attempt to reach an agreement on trade.
The two countries have not had formal trade talks since early June.
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An all-out trade war could overshadow Trump's otherwise solid economic record of low unemployment and stimulus-fuelled growth.
"Any unilateral threat or blackmail will only lead to intensification of conflicts and damage to the interests of all parties".
Trump has threatened to slap tariffs on virtually all of China's exports to the United States in the tit-for-tat trade conflict.
Announcing a higher tariff is required ahead of the hearings and will send a signal that the Trump administration is upping the pressure on China to make serious concessions.
Washington imposed 25 percent duties on $34 billion of Chinese goods on July 6 in response to complaints Beijing steals or pressures companies to hand over technology.
"The implementation date of the taxation measures will be subject to the actions of the U.S., and China reserves the right to continue to introduce other countermeasures", the Chinese government press release stated. "China is increasingly isolated with a weak economy".
Beijing can not match those measures dollar for dollar, as its exports far exceed imports.