South Korean stocks turned lower after starting a tad higher Monday, weighed down by concerns over the U.S. debt limit talks with the deadline only three days away, analysts said.

The benchmark Korea Composite Stock Price Index (KOSPI) lost 0.63 points, or 0.03 percent, to 2,024.27 in the first 15 minutes of trading.

Autos and insurers drove down the main index, with Hyundai Motor Group, the world's fifth-largest carmaker, slipping 0.2 percent and Samsung Life Insurance falling nearly 1 percent.

Top-cap Samsung Electronics traded up 0.07 percent.

The local currency was trading at 1,071.60 won against the U.S. dollar as of 9:15 a.m., down 0.2 won from Friday's close. (Yonhap News)