Government officials on Wednesday told diplomats they were still considering options for handling contaminated water at the disaster-hit Fukushima No. 1 nuclear power plant amid worries the water may be dumped into the ocean.

A massive amount of tainted water — more than a million tons as of August — is building up at the plant, crippled by a 2011 earthquake and tsunami, as operator Tokyo Electric Power Company Holdings Inc. tries to cool the melted fuel cores by pouring water over them.

Tepco has said it will run out of tank space by mid-2022.

The briefing for embassy officials in Tokyo follows a meeting in August of a government panel of experts looking into ways to solve the water problem. The final government decision will be made based on a report by the panel.

Asked by one of the participating embassy officials about the timing of the panel decision, officials said such timing has not been fixed, according to a media briefing held later in the day.

The briefing for diplomats was attended by 27 embassy officials from 22 countries and regions, including South Korea and the United States. No protests or demands have been made by the participating diplomats, according to the media briefing.

“With transparency in mind, Japan will continue providing the international community with information (on the Fukushima situation),” Koichiro Matsumoto, the Foreign Ministry’s director of international cooperation, told diplomats at the start of the meeting, the start of which was open to media.

The meeting comes after South Korea, locked in trade, territorial and historical rows with Japan, last month summoned a senior official from the Japanese Embassy in Seoul to ask about Tokyo’s stance on dealing with the Fukushima water.

But a Japanese Foreign Ministry official told reporters that briefings for diplomats on the matter have been held more than 100 times since the March 2011 disaster, and the one on Wednesday was held to pass information discussed at the latest government panel meeting in August.

Tepco’s revelation last month that it will run out of tank storage space in three years has put the tainted water issue back in the spotlight.

Previously, releasing the water into the sea had been generally considered the most viable option, but the government panel is now considering sticking with holding it at the facility for the foreseeable future due to strong objections from residents to discharging it into the sea.

Tepco claims that if the number of tanks continues to swell, that could slow the progress of other tasks necessary for scrapping the plant.