China's foreign ministry has defended the country's suspension of all seafood imports from Japan, as Japanese officials are considering bringing the issue to the World Trade Organization.

China imposed the ban on August 24, the starting date for the discharge of treated and diluted water from the crippled Fukushima Daiichi nuclear power plant into the ocean.

Japanese Chief Cabinet Secretary Matsuno Hirokazu said on Wednesday the government will take necessary steps within the WTO framework and through other channels also.

Some members of the main ruling Liberal Democratic Party are urging the government to consider filing a complaint with the WTO.

Chinese Foreign Ministry spokesperson Wang Wenbin told reporters on Wednesday it was "selfish and irresponsible" of the Japanese government to start releasing what he called "nuclear-contaminated water."

He said the discharge has been widely criticized by the international community and relevant preventive measures have been taken.

Wang added it is completely reasonable that Chinese authorities took emergency steps against marine products from Japan based on Chinese law and relevant WTO rules.

Chinese media outlets continue to criticize Japan over the treated water release.

An editorial of the Chinese Communist Party-affiliated newspaper Global Times criticized the Japanese government for condemning harassment phone calls pouring in from China.

The editorial claims that Japan is trying to portray itself as a victim of Chinese bullying in order to garner sympathy.

It says the core of the problem is not a dispute between China and Japan, but Japan's harmful act against humanity.

Those claims appear to reflect the authorities' stance, as Chinese media are under strict government control.

But no major protests in China have been reported so far.

The Japanese community in China is on alert ahead of anniversaries related to World War Two next month, including what Beijing calls Victory over Japan Day on September 3.