Containers pile up at a port. [File photo]

China's trade surplus in September?dropped to?12.4 percent to US$14.51 billion from a year ago, the General Administration of Customs (GAC) announced Thursday.

Exports and imports in the first nine months amounted to 2.68 trillion U.S. dollars, representing a 24.6-percent increase year-on-year.

From January to September, the total trade surplus shrank 10.6 percent to US$107.1 billion?compared to the same period of last year.

China yesterday strongly opposed?a currency bill passed in?the U.S. Senate against countries that were accused of undervaluing their currencies, saying that the passing of the bill would triger a trade war and increase risks undermining the global recovery.

The People's Bank of China, or China's central bank, said reform of the exchange rate will continue gradually to minimize any negative impact on the economy.