Seoul, Sep 25 (IANS): North Korean leader Kim Jong-un has offered an apology for the "unsavoury" killing of a South Korean official, the presidential palace in Seoul said on Friday.

In a formal notice sent to the South, the North conveyed Kim's message that he feels "very sorry" for greatly "disappointing" President Moon Jae-in and other South Koreans with the occurrence of the "unsavoury" case in its waters, instead of helping them amid their suffering from the coronavirus, Yonhap News Agency quoted Suh Hoon, director of national security at the presidential palace, as saying.

The North said the "unidentified" man, who crossed the western sea border without authorization, did not respond sincerely to its verbal security checks aboard a floating material about 80 metres away.

The North's troops shot two blanks, and he was seen as attempting to flee.

They then fired more than 10 gunshots at the distance of 40-50 meters under the related rules of engagement for maritime border security, according to the North's account.

While the North said that they did not find the official's body, South Korea's Joint Chiefs of Staff said that the North had set it on fire.

According to the Yonhap report, it is very unusual for a North Korean leader to apologize formally to South Korea.

The North has not yet formally apologized for the killing of a South Korean tourist to Mount Kumgang by its soldier in 2008.

It instead expressed its "regret" in a statement issued by a state tourism agency.