Japan is soon expected to summon Seoul's top envoy to Tokyo to protest a South Korean court’s decision to seize assets of a Japanese company in the South as requested by victims of Japan's wartime forced labor.

A diplomatic source said Wednesday that Japan's Foreign Ministry plans to call in Ambassador Lee Su-hoon later in the day to make a formal protest.

Last year, South Korea's Supreme Court ordered Nippon Steel & Sumitomo Metal to pay compensation to four South Koreans for their forced labor and unpaid work during World War Two.

After the Japanese firm refused to comply with the ruling, a court in Pohang recently approved the victims' petition for seizure of its shares of a joint company it runs with South Korea's POSCO.

Japan's Kyodo News reported that earlier on Wednesday, Japan's Cabinet decided to seek government-level consultations with Seoul based on a 1965 bilateral deal once the asset seizure is confirmed.

Japanese officials argue that all reparation-related issues tied to Japan's colonial rule of Korea were settled in the 1965 deal on normalizing diplomatic relations.