The European Central Bank's new quantitative easing (QE) measures could trigger "competitive depreciation" of currencies around the world, China's commerce ministry warned Thursday.

The ECB last week unveiled a programme to buy 60 billion euros ($68 billion) of private and public bonds each month starting in March, a move intended to ward off deflation in the eurozone.

The figure was more than the 50 billion euros expected by analysts, and the unprecedented scheme will total over 1.0 trillion euros.

"The European QE may worsen the competitive depreciation of currencies of various countries, further increasing the uncertainties in international cross-border capital flows," said China's commerce ministry spokesman Shen Danyang.

"We will closely monitor that," he told reporters at a briefing.

While the measures would make European exports cheaper and might help boost market confidence and growth in the eurozone in the short term, he added, their long run effects remained uncertain.

"It is still unclear whether in the mid-to-long term the QE can stop the eurozone economy from slipping into long-term stagnation and realise comprehensive recovery and growth," he said.

The European Union is China's largest trade partner. It is the Asian giant's top source of imports and its second-largest export market.

Shen said the impact of the stimulus on bilateral trade will be "both good and bad".

"The QE will push the euro to further depreciate, which is likely to lead Chinese companies expanding imports from Europe and lowering their investment costs in Europe.

"Meanwhile the weakening of the euro will affect Chinese companies's exports to Europe and Chinese firms' existing investment in Europe will also face the risks of suffering losses," he said.

According to Chinese data, two-way shipments increased 9.9 percent year-on-year to $615.1 billion in 2014, with China in surplus to the tune of $126.6 billion.