TOKYO: The Pacific island country of Micronesia, one of the fiercest critics of a Japanese decision to release water from the destroyed Fukushima nuclear plant into the sea, said on Friday it was no longer concerned about the plan.

Its president, David Panuelo, who said in a speech at the U.N. General Assembly last year he had the "gravest concern" about the dumping of the radioactive water, told reporters in Tokyo he was now comfortable with the release, due as soon as this spring.

"Our country is no longer fearful or concerned about this issue now as we trust in Japan's intention and technological capabilities in not harming our shared oceanic interests," Panuelo told reporters at the Japan National Press Club.

The Fukushima Daiichi nuclear station, about 220 km (130 miles) northeast of Tokyo, was badly damaged by a magnitude 9.0 earthquake and tsunami in March 2011, sparking three reactor meltdowns.

More than 1 million tonnes of water used to cool reactors in the aftermath of the disaster, enough to fill about 500 Olympic-sized swimming pools, is being stored in huge tanks at the plant.

Panuelo's change of stance clears a major obstacle to a plan that has met fierce resistance from Japanese fisherman and sparked similar protests from neighbouring countries including China, South Korea and other Pacific islands.

Japan has said regulators have deemed it safe to release the water, which will be filtered to remove most isotopes although it will still contain traces of tritium, an isotope of hydrogen hard to separate from water.

The 17-bloc Pacific Island Forum, which includes Micronesia, last month urged Japan to delay the release over fears fisheries would be contaminated.

Panuelo told reporters that the Pacific Island Forum would maintain consultations with Japan on the issue and that Micronesia's change in stance had come after "very, very thorough consultations" with Tokyo.

China's foreign minister raised the issue of the water release with his Japanese counterpart in talks on Thursday, according to a summary of a call between them published by China.

"China and the international community are seriously concerned about Japan's unilateral decision to discharge nuclear-polluted water into the sea, and hope that Japan will effectively handle it in an open, transparent, scientific and safe manner," China said.

A report on the talks issued by Japan's foreign ministry made no reference to the water release.