China's foreign exchange reserves stood at 3.11 trillion U.S. dollars at the end of May, down 14.23 billion U.S. dollars from a month earlier, central bank data showed on Thursday.

The amount, slightly higher than market forecast of around 3.10 trillion U.S. dollars, marks the second straight month of decline, according to the People's Bank of China (PBOC).

The State Administration of Foreign Exchange (SAFE) attributed the decrease to weaker non-dollar currencies and rising global asset prices. In May, the U.S. dollar index in the global financial market went up 2.3 percent.

However, cross-border capital flows and transactions remained generally stable, with balanced supply and demand in the forex market, it said.

The economy has maintained an improving trend, with economic structure continuing to optimize amid better growth quality and efficiency, the SAFE said on its website.

Looking ahead, the forex regulator said the country has the conditions and capability to maintain sound and stable growth momentum, and its foreign exchange reserves will remain generally stable.

According to the PBOC, the country's gold reserves remained unchanged in May at 59.24 million ounces, equivalent to 73.74 billion U.S. dollars.