Japan has proposed to China setting up a dialogue involving nuclear experts from both countries to discuss Tokyo's plan to release treated radioactive water from the crippled Fukushima nuclear complex into the sea, government sources said Wednesday.

China, which remains opposed to the plan, has yet to respond to the call for a working-level consultation, the sources said. Japan, which had received reassurance from the International Atomic Energy Agency over the plan's safety, aims to start the water release around this summer.

Tokyo and Beijing have been at odds over the planned discharge of water, which has gone through a process to remove most of the radionuclides, except tritium, into the Pacific Ocean from the Fukushima plant, wrecked by a devastating earthquake and ensuing tsunami in March 2011.

The sources said Japan hopes the experts' discussions can prevent China from politicizing the water discharge issue.

The envisaged move comes as China has begun blanket radiation testing on seafood imports from Japan, according to sources familiar with the bilateral relationship.

Chief Cabinet Secretary Hirokazu Matsuno said in a press conference in Tokyo on Wednesday that some of Japan's seafood exports to China have been stopped at Chinese customs.

Japan expects the talks to involve engineers of Tokyo Electric Power Company Holdings Inc., the operator of the Fukushima Daiichi nuclear power plant, as well as senior officials from related ministries and agencies from both countries, the sources said.

Since May, Japan has conducted briefings with the South Korean and Hong Kong governments to explain that the planned water release will not negatively impact human health or the environment.

One of the sources said Japan hopes to "create a framework with China similar" to what it has with South Korea and Hong Kong and "engage in continuous discussions" with Beijing.

Earlier this month, the IAEA concluded in a report submitted to the Japanese government that the plan aligns with global safety standards and will have "a negligible radiological impact on people and the environment."

But China has urged Japan not to go through with the plan, saying the IAEA's safety review does not constitute a "green light" for discharging what it calls "nuclear-contaminated water" into the sea.

The Japanese national flag flies in Tiananmen Square in Beijing in October 2018. (Kyodo)

Matsuno, the top Japanese government spokesman, urged China to have "discussions based on scientific evidence," saying the nation is disseminating "incorrect information."

Last Friday, while in Jakarta, Foreign Minister Yoshimasa Hayashi expressed his objection to "politicizing" the issue during talks with China's top diplomat Wang Yi.

Wang was quoted by the Chinese Foreign Ministry as saying Japan should "scientifically discuss various ways" to deal with the Fukushima water problem.

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