The U.S. team, led by Deputy U.S. Trade Representative Jeffrey Gerrish, included under secretaries from the Departments of Agriculture, Commerce, Energy and Treasury, and senior officials from those agencies and the White House.
USA stocks and European equities jumped as investors awaited developments on trade talks between the world's largest economies.
The statement came as trade talks between China and the United States were under way in Beijing, the first round of face-to-face discussions since both sides agreed to a 90-day truce in a trade war that has roiled global markets.
The U.S.is looking to crack down on China's business practices, including allegations of technology theft along with slashing the trade deficit and getting more access to Chinese markets.
Treasury officials have made the case that market volatility is in part due to the tightening of US monetary policy, and a result of the trade war with China.
Without a resolution, punitive United States duty rates on US$200 billion in Chinese goods are due to rise to 25 per cent from 10 per cent on Mar 2.
In what is widely seen as a goodwill gesture, China on Tuesday issued long-awaited approvals for the import of five genetically modified crops, which could boost its purchases of US grains as farmers decide which crops to plant in the spring.
Beijing might demand changes to US curbs on exports of "dual use" technology with possible military applications.
But a USA government official told AFP on condition of anonymity that "the trade talks have continued today (Wednesday)", without providing more information.
"At the beginning of 2018 the global economy was firing on all cylinders, but it lost speed during the year and the ride could get even bumpier in the year ahead", World Bank Chief Executive Officer Kristalina Georgieva said in a semi-annual report released late on Tuesday.
In public statements aides like Wilbur Ross, the commerce secretary, and Peter Navarro, a White House trade adviser, have played down the impact of the trade wars on markets, the USA economy and companies. The Chinese side has suggested talks were "constructive".
Mr Ross said there was a "very good chance" of reaching an agreement, although monitoring compliance would present a challenge.
China called it a violation of its sovereignty that has damaged "peace, safety and order" in the waterway.
"We urge the USA to immediately stop such provocative actions", Chinese foreign ministry spokesman Lu Kang told a regular press briefing, adding that Beijing had lodged a diplomatic complaint with Washington.
During that G-20 meeting - which took place in the early days of December in Buenos Aires - Xi agreed to a number of concessions in exchange for Trump agreeing to postpone a round of tariffs on Chinese goods.
Both Taiwan and Vietnam also claim the Paracel Islands, and the USA has contended that its ships passed through only worldwide waters, which Chinese officials refuted.
Fears have grown in recent months that the dispute is just one vector in a bilateral relationship that is fast cooling across the board, with top administration officials sharply criticizing Beijing for everything from human rights abuses and its influence operations in the United States.