South Korean President Yoon Suk-yeol has asked the International Atomic Energy Agency to help denuclearize North Korea.

Yoon met IAEA Director General Rafael Grossi in South Korea on Thursday.

Yoon's office says the president expressed concerns over Pyongyang's nuclear and missile programs which he described as increasingly sophisticated and accelerated.

Yoon requested the IAEA join efforts to denuclearize North Korea by strengthening its monitoring and inspection readiness posture.

Grossi stressed the IAEA would do its best to deter North Korea's nuclear provocations and safeguard the international non-proliferation regime.

Yoon also said people in South Korea are concerned about Japan's plan to release treated water from the damaged Fukushima Daiichi nuclear power plant into the sea. He asked the IAEA to conduct scientific and objective verifications of the Japanese project.

Grossi said his agency would publicize relevant documents in real time at every step of the procedure and closely communicate with South Korea.

Water used to cool molten nuclear fuel at the plant mixes with groundwater and rainwater that flows into the damaged reactor buildings.

The plant's operator, Tokyo Electric Power Company, is treating the water by filtering out most of the radioactive substances. But treated water still contains radioactive tritium and other radioactive substances.

The Japanese government and TEPCO hope to start releasing treated water around next spring after diluting it so the tritium concentration is below the level indicated by national regulations.

Meanwhile, Grossi also met with South Korean Foreign Minister Park Jin.

Park said the IAEA plays an indispensable role in monitoring Pyongyang's illegal nuclear development. He expressed his intention to bolster ties with the agency and work toward the complete denuclearization of North Korea.