The presidential office said it would conduct a probe and swiftly disclose its findings regarding North Korea's claim that South Korean drones violated its airspace.

The Office of National Security reaffirmed Sunday that Seoul had no intention of provoking the North, after Kim Yo-jong, the sister of North Korean leader Kim Jong-un, again raised the issue of a drone incursion in a morning statement.

The office said a joint military-police investigation would follow an initial military review and that the results would be released promptly.

It added that the government would continue efforts to ease inter-Korean tensions and build trust.

In a statement carried Sunday by the North's Korean Central News Agency, Kim Yo-jong said it was clear that South Korean drones had entered North Korean airspace and demanded a detailed explanation.

She nevertheless expressed appreciation for the South Korean Defense Ministry's announcement that it had no intention of provocation.

On Saturday, the Defense Ministry said it had not operated drones on the dates cited by the North and would thoroughly investigate the possibility that civilian-operated drones were involved.

President Lee Jae Myung also ordered a swift and rigorous joint investigation, warning that if civilians were found to have flown the drones, it would constitute a serious crime threatening peace on the Korean Peninsula and national security.