China's trade surplus narrowed 12.6 percent to around $160 billion in 2011, the commerce minister said Thursday, as the world's number two economy was hit by weaker demand from key export markets.

The drop from a 2010 trade surplus of $183 billion came after a year of economic turmoil that has seen a rebound in the United States and Europe slow down sharply.

Commerce Minister Chen Deming said total trade volume -- imports and exports combined -- rose more 20 percent to $3.6 trillion last year, according to the official Xinhua News Agency, which gave no breakdown.

Analysts said the shrinking surplus in 2011 from 2010 was in line with expectations as export growth clearly slowed.

"It was no surprise to see the surplus narrowing," Zuo Xiaolei, chief economist at Galaxy Securities in Beijing, told AFP.

"The external environment is the reason for export growth slowing down, but we should see a more significant increase in import growth," she said.

China's export growth fell from 31 percent in 2010 to an annual rate of 21 percent in the January-November period of 2011. The trade surplus was $138.4 billion in the first 11 has become a political hot topic as the United States and other countries claim Beijing keeps its yuan currency artificially low to boost exports.

US officials have long accused China of deliberately pursuing a weak currency, fuelling a flow of cheap exports that helped send the US trade deficit with China to more than $270 billion in 2010.

Chinese leaders have pledged to boost domestic demand to counter weakening overseas demand for its exports, a key driver of the country's economy.

Chen said last month China would move to "stabilise" its exports in 2012.

A Chinese government researcher also said last month that export growth would slow sharply this year, which could drag gross domestic product expansion below nine percent for the first time in more than a decade.

In a bid to boost growth and counter the slowdowns in Europe and the United States, authorities in December cut the amount of money banks must hold in reserve for the first time in three years.

The US Treasury said last month that China's yuan is still significantly undervalued, although it refrained from saying it manipulates the currency, which could lead to retaliatory action by Congress.

China defends its exchange rate regime, saying it is moving gradually to make the yuan more flexible.

He Maochun, a professor at Tsinghua University, said expanding imports would help reduce friction with trading partners, though he forecast China's overall trade balance would remain in surplus.

"China should keep expanding imports and maintaining exports. Not only will it help us build a sustainable economy at home, but also help reduce China's trade frictions aboard," he told AFP.

China's foreign trade volume was forecast to grow at an annual rate of 10 percent to reach $4.8 trillion by 2015, the commerce ministry said Wednesday as it issued development goals for the next four years.