Former UN chief Ban Ki-moon, who heads South Korea's national task force to combat fine dust, says countries must not fight each other, but fight air pollutants.

During a news conference on Thursday, Ban who chairs the National Council on Climate and Air Quality said the origins of the pollution need to be scientifically determined in order to enable real cooperation among countries.

But he said that, if countries pass the buck and delay action, efforts cannot move forward.

Ban said it would be good if Chinese President Xi Jinping discusses the issue with President Moon Jae-in when he visits South Korea, adding that, while working-level talks are being held, a top-down approach would be better.

He cited a similar situation in the 1980s and '90s when Sweden was hit by air pollutants from Britain. Ban said the two countries ended up wisely resolving the problem and Korea could take lessons from the way it was handled.

He also noted that fine dust is blowing in from North Korea, which has increased its coal use due to the oil sanctions imposed on it.