President Trump had repeatedly expressed discontent over the USA trade deficit with China, accusing the country of unfair trade practices, intellectual property theft, currency manipulation, and of providing state aid to Chinese firms.
China's surplus with the United States shrank marginally to $28.09 billion last month from a record $28.97 billion in June. An earlier round of tariffs that went into effect on July 6 applied to $34 billion in imports.
The United States and China implemented tariffs on $34billion worth of each other's goods in July.
Announcing the new duties, the US Trade Representatives Office: "China directs and unfairly facilitates the systematic investment in, and acquisition of, US companies and assets to generate large-scale technology transfer".
The first tariffs were imposed in March and China responded in April.
After a strong start to the year, growth in the world's second-largest economy cooled slightly in the second quarter, partly hit by the government's years-long efforts to tackle debt risks.
Exports rose 5 percent year on year while imports grew 12.9 percent, resulting in a trade surplus of 1.06 trillion yuan, which narrowed by 30.6 percent, according to the General Administration of Customs.
The trade balance between the two countries, which is at the center of the tariffs tussle, continued to be in favor of China.
The US will begin imposing 25% duties on an additional $16 billion in Chinese imports in two weeks, escalating a trade war between the world's two biggest economies.
For January-July, the surplus with the US rose to $161.63 billion, compared with about $142.75 billion in the same period a year ago.
Beijing has called on U.S. officials to be "cool headed", but fired back warning it would impose duties on an additional US$60 billion in United States goods, a threat the White House dismissed as "weak".
The U.S. levied 25 per cent duties on US$34 billion in Chinese goods on July 6, prompting swift in-kind retaliation from Beijing.
The US has said the tariffs are meant to penalise China for "unfair" trade practices, such as rules that compel companies in certain sectors to take on local partners if they want to do business in the country. US President Donald Trump accused Beijing of "being vicious" on trade, stressing that Chinese measures were targeting US farmers on goal.