South Korean stocks opened lower Wednesday on souring Sino-American relations, bucking overnight gains on Wall Street amid hopes of economic reopening.

The benchmark Korea Composite Stock Price Index (KOSPI) fell 6.49 points, or 0.32 percent, to 2,023.29 in the first 15 minutes of trading.

The weak start came after a news report suggested the US Treasury Department could freeze assets of Chinese officials and businesses in retaliation for China's new national security law.

The US and China are South Korea's two largest trade partners.

In Seoul, most large caps traded lower.

Market bellwether Samsung Electronics lost 0.81 percent and No. 2 chipmaker SK hynix slipped 0.85 percent.

Top automaker Hyundai Motor gained 0.41 percent, while its smaller affiliate Kia Motors shed 0.48 percent.

Leading pharmaceutical firm Samsung BioLogics slid 2.02 percent, with leading chemical maker LG Chem retreating 2.42 percent.

The local currency was trading at 1,234.70 won against the US dollar, down 0.40 won from the previous session's close. (Yonhap)