Japanese ministers indicated Tuesday the government might file a complaint to the World Trade Organization over China's decision to ban all Japanese seafood imports after treated radioactive water began being released into the sea from the crippled Fukushima nuclear plant.

Economic security minister Sanae Takaichi told a press conference, "We are entering a stage where we should consider countermeasures" against the import restrictions imposed by China, including filing a complaint to the global trade body, if "lodging a protest through a diplomatic channel is not effective."

Foreign Minister Yoshimasa Hayashi also said at a separate news conference that Japan will take "necessary steps under frameworks such as the WTO" and underscored the importance of "close communication" between the two countries, in order to maintain a "constructive" relationship.

Hayashi urged Beijing to immediately lift its import ban, imposed Thursday shortly after the nuclear complex began discharging the water into the Pacific Ocean, saying the measure is "not based on scientific grounds."

The two Asian powers have been at odds over the safety of the water being released from the Fukushima Daiichi nuclear power plant, which was severely damaged by the 2011 earthquake and tsunami, placing further strain on their unstable bilateral ties.

Seen as a critical step toward decommissioning the facility, the water discharge began after the International Atomic Energy Agency concluded in a report last month that the plan aligns with global safety standards.

Most radionuclides, except tritium, are removed from the water before discharge.

The Chinese government, however, has aired concerns about the impact of what it calls the "nuclear-contaminated" water and imposed the seafood import ban to "protect people's lives and health."

China has also prohibited food production operators from purchasing or using seafood originating in Japan to process for sale.

According to the Japanese central and local governments and plant operator Tokyo Electric Power Company Holdings Inc., no detectable amounts of tritium have been found in seawater samples taken near the site of the Fukushima complex.

The governments of Hong Kong and Macao, both semiautonomous regions of China, have banned seafood imports from Fukushima and nine other prefectures, with Macao having also banned various other food items from the areas.

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