But a declining surplus means that China probably will not face increasing pressure over its currency.

"I don't think the situation will get worse, although the pressure will be there for months", Zhu said.

China's surplus with the US fell to $18 billion in September, but the surplus with the EU climbed to $13.9 billion. Imports from the Association of Southeast Asian Nations accelerated, resulting in a deficit of $3.1 billion, the largest ever.

From January to September, China's exports to the US grew by 30.7 percent from a year earlier, while imports were up 33.8 percent, and the trade surplus reached $132.5 billion.

Li Wei, economist from Standard Chartered Shanghai, said that the September trade figures "suggest moderations in both export and import growths in China, but the prospects of near-term export growth were more of a concern than imports".

A report by Citigroup Global Markets agreed. "Going forward, export growth should continue to moderate under a slower growing global economy and a more expensive renminbi. Imports, however, should outpace exports in the coming months. A narrowing surplus and the steadily appreciating yuan should alleviate risks of 'currency war'. "

China speeded up foreign exchange rate reform in June and the yuan has gained more than 2 percent since then.

The US will unveil a currency report on Friday and decide whether to label China a "currency manipulator".

The US Senate is also considering legislation to impose duties on Chinese imports because of what some senators consider China's unfair currency advantage.

But central bank governor Zhou Xiaochuan said recently that a fast appreciation of the yuan is not a panacea for global economic imbalances. Premier Wen Jiabao said in Europe earlier this month that nations must work together to keep exchange rates of major reserve currencies relatively stable.