To further increase transparency, the Treasury looks forward China to disclosing foreign exchange market intervention regularly, the report said.

Overall, the report concluded that no major trading partner of the United States, including China, has manipulated their currencies over the past six months to keep them undervalued.

The US Omnibus Trade and Competitiveness Act of 1988 requires the Treasury to provide reports on whether its major trading partners manipulate the rate of exchange between their currency and the US dollar for purposes of preventing effective balance of payments adjustments or gaining unfair competitive advantage in international trade.

In previous such reports from the Obama administration, the US government did not label China as a "currency manipulator".

The market-based renminbi exchange rate reform will continue to proceed and renminbi exchange rates will become more flexible and be kept basically stable at an adaptive and equilibrium level, Yi Gang, deputy governor of the People's Bank of China, said at the IMF's annual meetings in Lima earlier this month.