China's trade surplus with the United States shrinks by 25 percent if calculated on a value-added basis, reflecting the high level of foreign-sourced content in Chinese exports, according to a new report published on Wednesday by the Organization for Economic Cooperation and Development and the World Trade Organization.

China's gross exports incorporate a large share of value from foreign sources and nearly half of all imported intermediates are used as inputs for exports, the report said. For example, nearly 40 percent of the total value of China's electronics exports comes from foreign sources.

The findings by the OECD and the WTO came amid a continuing debate on whether China should substantially appreciate the value of the yuan to address the trade imbalances it has with key trading partners such as the US and the European Union.