The world's nuclear watchdog gave its backing on Thursday to Japanese plans to release contaminated water from the damaged Fukushima nuclear plant into the ocean.
Japan has around a million tonnes of contaminated water stored in tanks at the site of the Fukushima Daiichi plant, whose reactors went into meltdown after a huge tsunami in 2011.
A government panel last month recommended the water be released into the ocean or vaporised, but no final decision has been taken, with all solutions deeply unpopular with sections of the Japanese public.
International Atomic Energy Agency (IAEA) director Rafael Grossi told journalists in Tokyo the panel's recommendations both appeared suitable.
"Of course the decision on what to do and when is a matter for the Japanese government," he said.
"Our final analysis is not completed but I can tell you already that we find the (panel) report based on a sound methodology and a systematic approach," he added, describing the two options proposed as "in line with well-established practices all around the world."
"But what is important is to do it in a way that is not harmful and you need somebody to monitor before, during and after release, to check that everything is okay."
"It's an issue of legitimate concern."