South Korea's benchmark Korea Composite Stock Price Index(KOPSI) weakened on Thursday on fears of new tariffs from the U.S.

U.S. President Donald Trump told his top trade official on Wednesday to consider raising tariffs on 200 billion dollars worth of Chinese goods to 25 percent from the ten percent rate his administration is currently mulling. 

The KOSPI ended the day one-point-60 percent lower after losing 36-point-87 points. It closed the day at two-thousand-270-point-20.

The tech-heavy KOSDAQ also fell, losing eight-point-87 points or one-point-12 percent to close the day at 781-point-38.

On the foreign exchange, the local currency weakened five-point-five won against the dollar, ending the session at one-thousand-126-point-one won.