SEOUL, South Korea (AP) — South Korea says North Korean leader Kim Jong Un has apologized over the killing of a South Korea official.

South Korea’s presidential office said Friday that Kim conveyed an apology in a message to South Korea. It cited Kim as calling the incident “unexpected” and “unfortunate.”

It’s extremely unusual for a North Korean leader to apologize to rival South Korea on any issue.

On Thursday, South Korea accused North Korea of fatally shooting one of its public servants who was likely trying to defect and burning his body after finding him on a floating object in North Korean waters earlier this week.

South Korean officials condemned North Korea for what they called an “atrocious act” and pressed it punish those responsible.