The employees are on strike after management rejected a proposal from mediators regarding bonuses. The strike is planned to last 18 days.
"The union will begin the planned strike tomorrow," the country's largest union wrote in a statement, according to the news agency .
The government has tried to mediate the conflict as a prolonged strike could damage South Korea's economy. According to Yonhap, semiconductor exports account for 35 percent of the country's total exports.
Samsung's stock fell 3 percent shortly after the strike announcement, according to CNBC .
Samsung said that the strike should not take place "under any circumstances".
"The union's unreasonable demands would risk undermining the fundamental principles of the company's management," the statement said, according to AFP.
