<P> Much like the Nixon visit to Beijing six years earlier, the formal establishment of Sino - US ties met with a mixed response from many countries . Taiwan, although fully expecting this step, nonetheless expressed disappointment at having not been consulted first . The reaction of the communist world was similar to 1972, with the Soviet Union and its allies in Eastern Europe mostly being noncommittal, Romania welcoming the move, and Cuba and Albania being strongly against it . North Korea issued a statement congratulating "our brotherly neighbors for ending long - hostile relations with the US". </P> <P> Vice Premier Deng Xiaoping's January 1979 visit to Washington initiated a series of important, high - level exchanges which continued until the spring of 1989 . This resulted in many bilateral agreements, especially in the fields of scientific, technological, and cultural interchange, as well as trade relations . Since early 1979, the United States and the PRC have initiated hundreds of joint research projects and cooperative programs under the Agreement on Cooperation in Science and Technology, the largest bilateral program . </P> <P> On March 1, 1979, the two countries formally established embassies in each other's capitals . In 1979, outstanding private claims were resolved and a bilateral trade agreement was completed . Vice President Walter Mondale reciprocated Vice Premier Deng's visit with an August 1979 trip to China . This visit led to agreements in September 1980 on maritime affairs, civil aviation links, and textile matters, as well as a bilateral consular convention . </P> <P> Sino - US military cooperation also began in 1979; American arms sales to China were initiated, and in 1981 it was revealed that a joint Sino - US listening post had been operated in Xinjiang, near the Soviet border . Chinese demands for advanced technology from the US were not always met, in part due to opposition from Congressmen who either distrusted technology transfer to a communist nation out of principle, or concern that there was no guarantee that such technology would not end up in the hands of unfriendly third parties . In 1983, the US State Department changed its classification of China to "a friendly, developing nation", thereby increasing the amount of technology and armaments that could be sold . The skepticism of some US Congressmen was not entirely unmerited as China during the 1980s continued to sell arms to Iran and other states that were openly hostile to American interests . </P>

When did the us start trading with china