South Korea on Monday put
Japan into its own new export category as President
Moon Jae-in called Tokyo's latest measures "very serious", intensifying a trade war between the two neighbours and US allies.
The move came after Seoul announced earlier this month it would remove Tokyo from its list of trusted trading partners, reciprocating an identical decision by Japan.
At a meeting with his top aides on Monday, Moon reflected on Japan's colonisation of the Korean peninsula in the first half of the 20th century to highlight the gravity of the situation.