Photo taken on May 16, 2018 shows an automatic container dock in Qingdao, east China's Shandong Province. (Xinhua file photo/Wang Peike)

China's foreign trade maintained steady expansion in the first seven months of this year amid mounting domestic and external challenges.

China's trade of goods rose 4.2 percent year on year in the January-July period to 17.41 trillion yuan (about 2.49 trillion U.S. dollars), data from the General Administration of Customs (GAC) showed Thursday.

Exports increased 6.7 percent year on year to 9.48 trillion yuan during the period, while imports grew 1.3 percent to 7.93 trillion yuan. China saw its trade surplus widen by 47.4 percent year on year to 1.55 trillion yuan during the same period.

In July alone, exports expanded 10.3 percent from a year ago to 1.53 trillion yuan, while imports went up 0.4 percent to 1.21 trillion yuan, leading to a 310.26-billion-yuan surplus, widening by 79 percent.

The steady trade growth came as the Chinese economy maintained strong resilience and sound fundamentals and at a time when internal and external risks and challenges were increasing, said Li Kuiwen, director of the GAC's statistics and analysis department

Meanwhile, China's trade mix continued to optimize as general trade with the long industrial chain and high value-added reported a higher proportion in the total trade since the beginning of this year, Li added.

General trade grew 5.7 percent year on year and accounted for 59.8 percent of the total trade in the January-July, 0.8 percentage points higher than the same period of last year.

The European Union remained China's largest trading partner in the period, with bilateral trade volume up 10.8 percent from one year earlier to 2.72 trillion yuan, followed by the ASEAN, up 11.3 percent to 2.35 trillion yuan, and the United States, down 8.1 percent to 2.1 trillion yuan.

China's trade with Belt and Road countries totaled 5.03 trillion yuan, up 10.2 percent year on year, six percentage points higher than the overall pace, said the GAC, adding that the amount accounted for 28.9 percent of China's total trade volume.

China's private businesses reported faster trade growth in the first seven months, with the trade volume increasing 11.8 percent to 7.31 trillion yuan. The amount accounted for 42 percent of the total trade volume in the period, up 2.9 percentage points year on year.

Thursday's data also showed that exports of mechanical and electrical products, as well as labor-intensive products such as textile and furniture, have all maintained growth in the period.

In addition, imports of crude oil and natural gas saw an increase, while iron ore and soybean imports dropped.