The radioactive wastewater from the Fukushima Daiichi nuclear plant is increasing by 170 tons each day.
As of late July, more than one million tons of contaminated water has accumulated in almost 1-thousand tanks at the plant.
While Japan is expected to run out of storage space for the wastewater within three years, global environmental NGO Greenpeace revealed last month that Tokyo has decided to discharge the wastewater into the ocean.
"The point is any releases from Fukushima, there will be, there will be migration of some of that material through the East China Sea into the East Sea."
To this, the Japanese government has insisted so far that it has not yet decided on how it will deal with the wastewater.
However, Japan's environment minister Yoshiaki Harada said Tuesday that there is no other way to dispose of the radioactive water other than to discharge it into the ocean.
According to local media, he told reporters that this is the only option as Tokyo Electric Power is said to be running out of room to store the radioactive water that was used to keep fuel cores from melting following the powerful earthquake in 2011.
Japan's Chief Cabinet Secretary Yoshihide Suga said in a separate briefing that what Harada said was his personal opinion.
"I understand that Harada's comment means that the government should fully discuss the matter, and it was his personal opinion."
In response, Seoul's foreign ministry said that the remarks are not Japan's official stance, adding that the Seoul government is keeping a close watch on Tokyo's movements.
Stressing that the issue deals with the public's health and safety, the ministry asked Japan to take a wise and prudent decision on the matter.
Kim Hyo-sun, Arirang News.