"We thought in the face of the financial crisis, there would be a spirit of self-criticism beneficial to finding ways of resolving the issue and overcoming the crisis," Su said, adding that it was imperative to avoid any excuses to encourage trade protectionism.
In answers to questions submitted by the Senate Finance Committee, Geithner wrote that Obama, backed by the conclusions of a broad range of economists "believes that China is manipulating its currency."
However, Geithner also suggested that now might not be the right time to brand China as a currency manipulator under U.S. trade law, a designation that would trigger negotiations between the two countries and could result in U.S. economic sanctions against China.
He said Obama has pledged to use all the diplomatic avenues open to him to seek change in China's currency.
China has allowed the value of its currency to rise by 21 percent over the past two years. But American manufacturers complain that the Chinese yuan is still significantly undervalued, making Chinese goods cheaper for U.S. consumers and American products more expensive in China.