BEIJING -- China's central bank reiterated on Thursday the country's currency, the yuan, will remain "basically stable at a rational and balanced level".

The People's Bank of China also promised in a report that market forces would play a bigger role in determining the yuan's value, and that the currency would gradually be made more flexible.

U.S. manufacturers argue the yuan is undervalued by as much as 40 percent, making Chinese goods cheaper in the United States and American products more expensive in China.

China's trade surplus with other countries hit a record of 14.6 billion U.S dollars in July, a rise of 40.6 percent over the same month last year, the General Administration of Customs reported Thursday.

In July last year, the government allowed the yuan to appreciate by about two percent against the U.S. dollar and dropped its peg to the dollar in favor of a restricted float against a group of foreign currencies.

The yuan has since risen by more than three percent. The official exchange rate was at 7.9688 per U.S. dollar on Thursday.