The world's two biggest economies are locked in a trade dispute over Washington's charges that China uses predatory tactics in a drive to supplant USA technological supremacy.
A first tranche, on $34bn worth of goods, went into effect in July.
The Chinese government responded and said Beijing will also slap additional import tariffs of 25% on $16 billion worth of United States goods ranging from oil and steel products to autos and medical equipment.
China's trade with the US also continued to rise in July despite the tariffs, with exports up 11.2 percent year-on-year, and imports increasing 11.1 percent.
August 1: Washington more than doubles the value of its tariff threats against Beijing, announcing plans to increase the size of proposed duties on $200 billion worth of Chinese goods to 25% from 10%.
A weaker yuan, which marked its worst 4-month fall on record between April and July, may have taken the sting out of 25 percent tariffs on $34 billion exports to the United States.
On Tuesday, the administration said it had made a decision to go ahead with tariffs on 279 of the 284 items added in June; they're worth about $16 billion a year.
Trump has threatened to levy a 25% tariff on an additional $200 billion worth of Chinese imports to the U.S. - a move that would blow open the disagreement between the countries.
Although the move was expected, it solidifies the view that there appears to be no effort underway to defuse the dispute between the world's two largest economies.
The US and China have been trying to restart high-level talks that broke off after Trump followed through on his tariff threats.
The government has responded by releasing more liquidity into the banking system, encouraging lending and promising a more "active" fiscal policy.
Trump's mission to reduce the USA trade deficit via the threat of tariffs has brought him into conflict with China as well as United States allies, roiling financial markets and raising fears of a global trade war the International Monetary Fund has warned may undermine the strongest economic upswing in years. That was off slightly from June's 13.6% rate but still stronger than China's global export growth.
Of more direct effect in the Sino-U.S. trade war, China's surplus with the United States shrank only marginally to $28.09 billion last month from a record $28.97 billion in June. Washington has long criticised China's trade surplus with the United States and has demanded Beijing cut it. Beijing is expected to hit $16 billion worth of U.S. goods with equal tariffs in response to Tuesday's move.