The head of the International Atomic Energy Agency has told NHK that "full transparency" is the key to tackling misinformation and confusion surrounding the release of treated and diluted water from the Fukushima Daiichi nuclear power plant into the ocean.

IAEA Director General Rafael Mariano Grossi, who is now visiting Japan, spoke to NHK on Tuesday.

He is scheduled to inspect the Fukushima Daiichi plant on Wednesday to see how the discharge operation is being carried out.

Grossi mentioned that the IAEA is independently monitoring the safety of the treated water and said Japan's plan for the treated water release conforms to international safety standards.

He added that what's important is whether the plan is executed as intended.

Water used to cool molten fuel at the plant has been mixing with rain and groundwater. The accumulated water is being treated to remove most radioactive substances, but it still contains tritium.

Before releasing the treated water into the ocean, the plant's operator dilutes it to reduce the tritium levels to about one-seventh of the World Health Organization's guidance level for drinking water.

When asked about the response to countries such as China that oppose or express concerns about the release, Grossi said that there is ongoing dialogue which he hopes will help resolve the concerns.

He said he has the impression that the people in these countries are gradually understanding the situation regarding the treated water.

Grossi went on to say that some people are afraid of the treated water, and there is a lot of misinformation and confusion. He stressed that "full transparency" of information is the only "antidote" to dealing with the matter. He added that the IAEA will share the scientific data with various countries to promote understanding.