Experts from the International Atomic Energy Agency will arrive in Japan in late November to undertake joint radiation monitoring of the sea around the Fukushima No. 1 plant, the Nuclear Regulation Authority said Thursday.

The decision was conveyed during talks between the NRA's commissioners and visiting IAEA Director General Yukiya Amano in Tokyo. The U.N. watchdog's experts are expected to study the monitoring activities of domestic authorities and Tokyo Electric Power Co., an NRA official said.

Concerns remain among neighboring countries about the impact of radioactive materials that continue to spill from Fukushima No. 1, which suffered three core meltdowns from the quake-tsunami disaster in March 2011. Most recently, these fears have centered on the 300 of tons of contaminated groundwater spewing into the Pacific every day.

"Sea monitoring is very important. The IAEA will very much like to cooperate," Amano told NRA Chairman Shunichi Tanaka at the outset of the meeting.

The Vienna-based watchdog's participation is expected to help increase, somewhat, the credibility of data released by the Japanese government and Tepco about the nuclear disaster.

A massive amount of toxic water is stored in tanks at the No. 1 plant, but leaks have occurred repeatedly. The government earlier said radioactive contamination of the sea has only been observed within the facility's harbor, an area less than 0.3 sq. km.