In his Liberation Day address marking Korea's independence from Japan's 1910-45 colonial rule, Moon refrained from deriding Japan but laid out ambitious goals for inter-Korean relations, including an unprecedented call for unification by 2045.

Moon warned the global free trade order may suffer if a country "weaponises" a sector where it has an upper edge, referring to curbs Japan has imposed on exports of some high-tech materials to South Korea.

Seoul calls the move as retaliation over a feud about wartime forced labour, while Tokyo cites unspecified security reasons.

The dispute, triggered after a South Korean court ordered Japanese firms last year to compensate some of their former labourers, has brought their ties to their lowest ebb in more than half a century.

Japan says the issue was settled by a 1965 treaty normalising bilateral ties.

But Moon said the two neighbours can overcome the past and move toward the future if Japan "contemplates a past that brought misfortune to its neighbouring countries".

"Better late than never: if Japan chooses the path of dialogue and cooperation, we will gladly join hands," Moon said.

Moon also painted a brighter outlook for the two Koreas, vowing efforts for a successful joint hosting of the 2032 Olympics and an eventual unification by 2045.

Such goals have long been considered distant, but come at a particularly sensitive time amid the North's ongoing series of missile tests, stalled nuclear talks with the United States and virtually severed inter-Korean communications.

Australian Associated Press