The US on Tuesday published a list of $200 billion (€170 billion) worth of Chinese goods that could soon be hit with tariffs.
All told, Trump has threatened eventually to slap tariffs on up to $550 billion in Chinese imports - more than China actually exported to the United States a year ago - if Beijing won't relent to USA pressure and continues to retaliate.
The U.S.is pursuing a new set of tariffs that would hit $200 billion in Chinese goods, according to senior administration officials.
The United States began imposing tariffs on $34 billion in Chinese goods at 12:01 a.m. EDT (0401 GMT) on Friday.
USA officials say they remain willing to bargain.
The White House has complained that China has used predatory practices in a relentless push to grant Chinese companies an unfair advantage in the industries of the future, including robotics, electric cars and biopharmaceuticals.
A senior administration official told Fox News that China has been "non-responsive" to USA actions and has insisted that Beijing does not see any way America has been hurt by Chinese policies.
Chinese retaliation: China has threatened to retaliate dollar-for-dollar if the Trump administration imposes a new round of tariffs.
China's retaliation to those measures was "without any global legal basis or justification", Lighthizer said Tuesday.
"As in the past, the United States is willing to engage in efforts that could lead to a resolution of our concerns about China's unfair trade practices and to China opening its market to USA goods and services", he added.
The tariffs could take effect after public consultations end on August 30, according to a statement from the US Trade Representative's office Tuesday. That's why Trump can slap tariffs on them just because he feels like it. "This new round of proposed tariffs takes the fight onto yet another level from which it is going to be hard for either side to make a graceful retreat", said Eswar Prasad, former head of the International Monetary Fund's China division.
"Unfortunately, China has not changed its behaviour - behaviour that puts the future of the United States economy at risk".
The U.S.is now considering levying duties on a further $16 billion in Chinese goods, after a public hearing later this month.
The move, which was expected, escalates a trade war with China.
The Washington Post's Danielle Paquette reported from Beijing.