South Korean experts have held final talks with Japanese government officials and others on Japan's plan to discharge treated and diluted water from the crippled Fukushima Daiichi nuclear power plant into the ocean.

The delegation of about 20 members includes senior officials of South Korea's Nuclear Safety and Security Commission, as well as marine environment specialists. They examined the nuclear plant on Tuesday and Wednesday.

The delegation met with officials of the Economy, Trade and Industry Ministry as well as the Nuclear Regulation Authority at the Foreign Ministry on Thursday. The meeting was held behind closed doors.

The South Korean side reportedly asked for additional data on analyses of the treated water and the facility for discharging it.

Japan plans to release treated water after diluting it to reduce tritium levels to one-seventh of the World Health Organization's safety standards for drinking water.

The plant's operator, Tokyo Electric Power Company, is preparing to carry out the plan by around this summer.

People in South Korea have raised concerns about the plan. The experts say that they will review the safety of the plan after they return home on Friday and report their findings to the South Korean people.

The Japanese government says the delegation's visit was aimed at deepening the understanding of the South Korean side. Japan says it aims to disseminate information on the safety of the plan following the assessment by the International Atomic Energy Agency, which is expected to be issued by June.