In Seoul, the Foreign Ministry is considering a plan to retaliate against Japan's fishing ban.
The Foreign Ministry first plans to ask the Japanese government to withdraw the ban before taking retaliatory actions. A ministry official said if Japan ignores South Korea's demand, Seoul will impose a fishing ban on Japanese vessels in South Korea's exclusive economic zone. The ministry has started to study what areas of waters Japanese vessels might be denied access to and what kind of fish they will be banned from catching.
On Monday, Foreign Minister Han Seung-soo plans to summon Japanese Ambassador Terusuke Terada to his office to file an official protest.
Earlier this week, Japan announced it was withholding approval for South Korean vessels to fish in the disputed waters. The move came after South Korea negotiated an agreement with Russia that allows South Korean vessels to fish in Japan's northern waters from July.
The Soviet Union seized the islands from Japan at the close of World War Two, but Tokyo still claims sovereignty.
South Korea insists that the Korea-Russia agreement has nothing to do with territorial dispute between Russia and Japan. Seoul also believes that Tokyo's fishing ban severely infringes on the basic spirit of the Seoul-Tokyo fishing accord signed last year.