China's exports face downward pressure in the third quarter amid a severe and complex economic environment, but trade may continue to stabilize in the second half of the year, the General Administration of Customs said on Wednesday.

The country's leading export indicator started to drop in May after reaching a peak in April, which indicates increasing downward pressure, customs spokesman Huang Songping told a news conference in Beijing.

"The world economy still faces many uncertainties, including Brexit, expectations of an interest rate hike by the US Federal Reserve, volatile international financial markets and the threat of terrorism. These will all affect the confidence of consumers and investors globally and curb international trade," Huang said.