China's trade surplus widened less than expected in June, according to official statistics.
In June, China's trade surplus came in at $US27.12 billion ($A29.85 billion), after a May result of $US20.43 billion.
Bloomberg analysts forecast a trade surplus of $US27.8 billion.
Exports in the month decreased by 3.1%, against expectations of a 3.7% rise.
Imports shrank by 0.7%, well below expectations of a six% increase.
Customs spokesman Zheng Yuesheng says China's foreign trade is "facing grave challenges".
The main cause was "prolonged sluggish foreign demand", followed by rising export prices in foreign currency terms, labour costs, and a deteriorating trade environment due to rising trade disputes, he said.
But the trade surplus for the first six months of 2013 was substantially higher than the same period last year, the statistics showed, up 58.5% to $US107.95 billion.
First half exports rose 10.4% to $US1.05 trillion and imports increased 6.7% to $US944.87 billion.
Mr Zheng said the factors bedevilling China's trade situation are likely to linger over the short term.
"Trade still faces a complicated and volatile situation in the second half of the year and there are a lot of difficulties and challenges," he said.
Alarm bells have rung over the health of China's rebound from a prolonged downtrend as trade and manufacturing conditions have worsened this year.
China's economy grew 7.8% in 2012, its worst performance in 13 years, on the back of slack demand for exports and weakness at home.
The first three months of the year saw expansion of just 7.7%, disappointing analysts who had expected growth to accelerate after showing strength at the end of 2012.
The government has set a growth target for 2013 of 7.5%, the same as last year's, as it looks to retool its economic model from exports to domestic consumption.
Beijing is due to announce gross domestic product (GDP) figures for the second quarter on Monday.
China's June trade figures came after the International Monetary Fund (IMF) on Tuesday cut its global economic growth forecast, citing new downside risks in key emerging-market economies and a deeper recession in the eurozone.
The IMF projected the world economy to expand 3.1% in 2013, down from its April estimate of 3.3%.
China and other emerging economic powers now face new risks, it warned, "including the possibility of a longer growth slowdown".
On Tuesday, the government announced that China's inflation accelerated to 2.7% in June, but analysts cautioned that demand remained weak and second-quarter economic growth may have slowed further.
The year-on-year figure for the consumer price index - a main gauge of inflation - was up from 2.1% in May, the National Bureau of Statistics (NBS) said.