"The influence of Congress on U.S. policy toward China, once significant because so much hung on the annual possibility that favorable trade terms could be suspended, has more recently been diffused. Sanctions that remain in place today can all be modified, eased, or lifted altogether by the President, without congressional input (though some changes would require that the President notify Congress). Congress and the Administration each recognize the importance of China's emerging ability to consume and to produce, and China has become an increasingly important trading partner of the United States. At the same time, because of the unrelenting tension between the United States and the Peoples Democratic Republic of Korea over the latter's interest in developing nuclear weapons capability, and because of China's longstanding relation with North Korea as a primary trading partner and benefactor, the United States relations with China are crucial."
CRS Report for Congress, RL31910