South Korea’s Foreign Ministry on Monday summoned the economy minister from the Japanese Embassy in Seoul to discuss a reported plan to discharge waste water, contaminated due to the meltdown at the Fukushima No. 1 nuclear plant, into the Pacific Ocean.

Ministry official Kwon Se-jung, whose brief covers climate change and environmental affairs, called in diplomat Tomofumi Nishinaga to address growing public concern over the plan.

Kwon delivered a note verbale and asked for Japan to state officially how the water will be disposed of, the ministry said in a statement.

Nishinaga said he would report back to Tokyo. He said Japan will explain transparently what will happen to the water, not only to South Korea but also the international community.

Environmental groups and activists, such as Greenpeace, have warned of potential dangers if the water, contaminated with tritium, is released into the Pacific. They underscored the effect it would have on South Korea.

Last week, South Korea’s Foreign Ministry spokesman Kim In-cheol said that the ministry would take active measures regarding the discharge plan.