South Korean firms' business sentiment slipped to a 26-month low this month due to concerns of a trade war between the U.S. and China. 

According to the Bank of Korea on Friday, the business survey index(BSI) for December for all industries came to 72, down two points from the previous month. 

The index marks the lowest level since October 2016, when it stood at 71. 

The BSI for manufacturers came to 71 for December, also down two points from a month earlier. 

A reading below 100 means pessimists outnumber optimists.

The economic sentiment index combining the BSI and the consumer sentiment index fell to a 28-month low this month.