Japan lodged a complaint to China at a Group of 20 meeting on Thursday over Beijing's blanket import ban on Japanese seafood. The Chinese measure is in response to the release of treated and diluted water from the Fukushima Daiichi nuclear power plant into the Pacific Ocean.

China's customs authorities announced the immediate ban on Thursday, after Tokyo Electric Power Company started releasing the water earlier in the day.

Japan's State Minister for Foreign Affairs Yamada Kenji told reporters that he voiced the protest at the meeting of the G20 trade and investment ministers in the Indian city of Jaipur.

Yamada said the decision to release the water has acquired understanding and support from many countries.

He said this follows briefings given to the international community that were based on science and done with transparency.

Yamada added China's measure is unscientific and completely unacceptable. He demanded that Beijing lift the ban immediately.