National Police Commissioner General Yoon Hee-keun has reiterated that pepper spray may be used in response to illegal acts during a large-scale rally set to be held by one of the nation's umbrella unions on Wednesday.

Speaking to reporters, the police chief said he had ordered on-site commanders to make a decision depending on the situation. The police have not used pepper spray to disperse rallies since March 2017.

Yoon said the police plan to break up the rally if the event exceeds its permitted time period or the attendees cause excessive traffic inconveniences.

Asked whether the police were toughening their response, the chief said he cannot agree with those suggesting that the use of the spray is equivalent to a crackdown, adding that the agency plans to fulfill its duty against illegalities committed under the pretext of freedom to assemble.