TOKYO, March 13 (Xinhua) -- International Atomic Energy Agency (IAEA) Director-General Rafael Grossi emphasized continued efforts in monitoring Japan's ocean discharge of nuclear-contaminated wastewater from the crippled Fukushima Daiichi Nuclear Power Plant, local media reported on Wednesday.

The IAEA chief reiterated the organization's commitment to further monitoring the discharge as he met with local fishermen in Iwaki City of the northeast prefecture of Fukushima during a three-day trip in the country.

Underscoring that the discharge marks merely the initial phase of a long process, Grossi stated that "much effort will be required in the lengthy process ahead," national news agency Kyodo reported.

Grossi, emphasizing the IAEA's role as an independent observer, reiterated the organization's stance on maintaining vigilance throughout the process.

The visit to Fukushima Prefecture marks Grossi's first since July last year and notably, his first visit following the commencement of the discharge. He is also expected to inspect the Fukushima Daiichi nuclear power plant to assess the discharge later in the afternoon.

While the Japanese government and the plant's operator Tokyo Electric Power Company (TEPCO) have asserted the safety and necessity of the discharge, concerns have been raised by neighboring countries and local stakeholders regarding potential environmental impacts.

Last month, TEPCO started its fourth round of release of the nuclear-contaminated wastewater from the power plant into the Pacific Ocean.