South Korean Prime Minister Han Duck-soo urged Rafael Grossi, director general of the International Atomic Energy Agency, to ensure the country's continued engagement in the safety review of the Fukushima Daiichi nuclear power plant’s wastewater before its release, Han's office said in a statement Wednesday.

Han stressed that South Korea's experts and research institutions must be included in IAEA's safety assessment of some 1.3 million metric tons of treated wastewater in Japan before its release by as early as this year. The controversial planned discharge comes 12 years after a massive earthquake and tsunami that triggered three reactor meltdowns at the Fukushima Daiichi nuclear power plant in eastern Japan.

Currently, samples of the wastewater diluted with seawater are being monitored by the Korea Institute of Nuclear Safety, according to the government.

Han also told Grossi that the IAEA's final approval over Japan's discharge of treated wastewater must be based on a scientific and objective viewpoint and abide by international standards.

Grossi said Tuesday on his Twitter account that the talks revolved around "important exchange on nuclear safety in the (East Asian) region."

South Korea is one of 11 countries to have taken part in the IAEA task force to assess the safety of the nuclear-contaminated water for release.

Han's remarks came a few days after South Korean President Yoon Suk Yeol and Japanese Prime Minister Fumio Kishida agreed on Seoul's dispatch of a group of experts to inspect the safety of the wastewater later in May. The purpose of the inspection is "not to evaluate or certify the safety of treated water," according to a Japan Times news report that quoted Japanese Industry Minister Yasutoshi Nishimura as saying on Tuesday.

This was part of the agenda during the talks held between Han and Grossi at the Vienna International Center, where IAEA headquarters is located, during his trip to Austria. The talks also centered around continued monitoring of North Korea's nuclear threats.

Austria was his third stop during his eight-day trip to various European countries. Han attended King Charles III’s coronation Saturday in the United Kingdom before heading to Sweden. Romania is Han's next destination.

Korea established trade ties with Austria in 1892.