Geng said China had shown sincerity by still sending a high level delegation to the United States for talks last week and that China has remained calm in the face of pressure.
The list "covers essentially all products" not already affected by punitive tariffs, the USTR said.
However, the onshore yuan weakened 0.1% to its lowest level since December 27, 2018, trading at 6.8874 per dollar, after the foreign ministry said it hoped the United States would not underestimate China's determination to defend its interests.
But when asked whether China was making preparations for a possible Xi-Trump meeting, Mr Geng said: "I have no information at present about the specific question raised".
The trade war between the world's two largest economies escalated on Monday with China slapping tariffs on Dollars 60 billion worth of U.S. imports in a retaliation to Trump's move to raise tariffs on USD 200 billion worth of Chinese goods.
Among the 3,805 categories of Chinese imports that would be newly subject to a 25 percent tariff are cellphones, computers, and other consumer electronics, the trade representative said, adding that pharmaceuticals, certain medical products, rare-earth and "critical" minerals would be exempt from the new duties.
The retaliation measure came three days after the U.S. moved to increase tariffs on US$200 billion worth of Chinese goods from 10% to 25% as of May 10.
Trump also defended his administration's trade efforts with China as a model for USA negotiations with other nations. They said that loss could widen to one percentage point if both sides extend penalties to all of each other's exports.
On Wall Street, the Dow Jones Industrial Average climbed 347.87 points, or 1.37%, to 25,672.86, the S&P 500 gained 38.53 points, or 1.37%, to 2,850.4 and the Nasdaq Composite added 122.52 points, or 1.6%, to 7,769.54.
After yesterday's dynamic selloff in US equities, and respectable gains in gold, today's reverse bounce was to be expected.
That move underscored worries about the economic impact of a trade war, given a sustained inversion of this part of the yield curve has preceded every US recession in the past 50 years.
If he tries to pass along the higher costs from the new tariff on toys to customers, he said, he will lose sales.
Beijing unleashed its tightly controlled media this week after keeping a lid on rhetoric for months as the trade war with Washington reignited, with fiery clips from state media ricocheting around the Internet.
"This is only too belatedly they've accepted the fact that it is a trade war", he said.
"Other countries are already negotiating with us because they don't want this to happen to them".
Max Baucus, a former United States ambassador to China told CNN: "China feels it does not have to give in".
"President Trump seems to think that the tariffs are good for the economy". Obviously, Americans and American consumers are paying more and more by the day. It's not clear to me that the president's policies are addressing that, but we'll see. "They must be a part of U.S. action", he added.
Analyst David Lampton, a fellow at the Stanford Asia Pacific Research Center in Palo Alto, California, said he sees the United States and China as competing to be more than just a dominant economic force.
"The sentiment out in farm country is getting grimmer by the day", said John Heisdorffer, the chairman of the American Soybean Association.