China's August trade surplus was the second highest this year, adding to pressure for Beijing to ease currency controls.
The trade figures released Friday showed that export growth weakened in August but not dramatically. Imports rebounded, in a sign the slowdown in the world's second-largest economy might be less severe than expected.
The surplus _ $20 billion in August _ will add to mounting demands by Washington and others for Beijing to ease currency controls that they say keep its yuan undervalued and give Chinese exporters an unfair advantage.
American lawmakers set aside criticism as the two governments worked together to ease the global crisis but threats of possible trade sanctions have resumed as they face pressure to create jobs ahead of November elections.
"The likelihood of congressional action targeting China for pegging its currency to the dollar is increasing at an alarming rate," said economist Derek Scissors of the Heritage Foundation in Washington in a report.
August export growth fell to 34.4 percent over a year earlier from July's 38.1 percent, the Chinese customs agency reported. But import growth rebounded to 35.2 percent from the previous month's 22.7 percent.
The trade surplus narrowed from July's 18-month high of $28.7 billion but was up 28 percent from a year earlier.
U.S. legislators have scheduled two congressional hearings this month on China's currency and congressional leaders have expressed interest in seeing possible retaliatory measures enacted.
The U.S. Commerce Department in August declined to launch an investigation of the currency complaints despite requests by some lawmakers.
In June, Beijing ended an 18-month-old link between the yuan and the dollar and said it would allow a more flexible exchange rate, but the Chinese currency has risen by only 0.6 percent since then.