Rising exports have given China its largest trade surplus in two and a half years in spite of economic problems in much of the world.

The government said Monday it posted a $31.5 billion surplus in July, driven by a record $175 billion in exports. That marked a 20.4 percent increase in exports over the previous July.

Chinese imports were also up strongly at 22.9 percent, boosting hopes that Chinese purchasing can help lift other struggling economies.

China’s huge surpluses have been a source of friction with its major trading partners, who say Beijing artificially depresses the value of its currency to gain an unfair advantage. But analysts expect the nation’s export growth to slow because of weak demand in the United States and Europe.