A team of experts from the International Atomic Energy Agency is visiting Japan to inspect the discharge of treated and diluted water from the crippled Fukushima Daiichi nuclear power plant into the ocean.
The IAEA task force is conducting a safety review for the second time since the discharge operation began in August last year.
Experts from countries including the US, South Korea and China visited the Foreign Ministry in Tokyo on Tuesday.
They met officials from the industry ministry and Tokyo Electric Power Company, which manages the Fukushima plant.
IAEA coordinator Gustavo Caruso said the experts will visit the Fukushima Daiichi plant to follow up on technical topics that are important for safety.
He said, "This independent, objective and science-based approach will help build confidence" in Japan and beyond.
The task force members are due to stay in Japan until Friday. They plan to see the water discharge process and meet officials from the Nuclear Regulation Authority and other organizations.
The Fukushima Daiichi plant suffered a triple meltdown in the 2011 earthquake and tsunami.
Water used to cool molten fuel has been mixing with rain and groundwater. The accumulated water is being treated to remove most radioactive substances, but 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.