The operation came as Chinese and U.S. officials kicked off talks in Beijing to find a solution to a bitter trade war that prompted the two sides to impose tariffs a year ago on more than $300 billion in total two-way trade.
USA delegation member Steven Winberg, who is a United States assistant secretary for fossil energy, said on Tuesday that the talks are going on well so far, according to a report from Reuters.
Lu also said Vice President Wang Qishan would attend the annual World Economic Forum in Davos, Switzerland in late January, but added that he had not yet heard of any arrangements for a meeting with Trump there.
Deputy U.S. Trade Representative Jeffrey Gerrish is leading the American delegation in Beijing. He added the USA has rebuilt China and he didn't believe they were ready to negotiate yet.
US President Donald Trump also said trade talks were going "very well", and he was confident that both sides will come to an agreement.
U.S. Undersecretary for Trade and Foreign Agricultural Affairs Ted McKinney, center, who is part of U.S. trade delegation leaves from a hotel for a second day of meetings with Chinese officials in Beijing, China, Tuesday, Jan. 8, 2019.
Ministry spokesman Lu said Monday during a routine briefing that Chinese military aircraft and naval vessels were dispatched to identify the USA vessel and warn it to leave the area near disputed islands in the South China Sea.
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. Wilbur Ross, U.S. Trade Representative Robert Ligthhizer, National Economic Council Dir.
The United States and China will continue trade talks in Beijing for an unscheduled third day, USA officials said on Tuesday amid signs of progress on issues including purchases of U.S. farm and energy commodities and increased access to China's markets. The move prompted China to increase tariffs on Dollars 110 billion of USA goods.
Trump imposed tariff increases of up to 25 percent on $250 billion of Chinese imports over complaints Beijing steals or pressures companies to hand over technology.
Ross said there was a "very good chance" of reaching an agreement, although monitoring compliance would present a challenge.
For their part, Chinese officials are unhappy with US curbs on exports of "dual use" technology with possible military applications.
The Global Times said China's growing economy means it can "carry out a more intense boycott" of trade with the United States if needed.
As the Trump administration continues trade negotiations with China, the USA delegation is taking additional steps to make sure the Communist country follows through on its pledges. He is pushing to address concerns of China's alleged theft of intellectual property and market-access barriers, as well as to demand structural economic reforms.
The U.S. economy grew at an annual rate of 3.4 percent in the third quarter, and unemployment is at a five-decade low.
For their part, Chinese officials are unhappy with US curbs on exports of "dual use" technology with possible military applications. They complain China's companies are treated unfairly in national security reviews of proposed corporate acquisitions, though nearly all deals are approved unchanged.