Leaders of Pacific island nations expressed strong concerns over the release of treated radioactive water from Japan's wrecked Fukushima No. 1 nuclear plant into the Pacific Ocean during a regional summit, according to Cook Islands Prime Minister Mark Brown.

Brown, who currently chairs the Pacific Islands Forum, said Thursday there were "strong concerns" raised by "our forum leaders for the significance of potential threats of contamination to the health and security of the blue Pacific."

The bloc's 18 members have expressed differing views on the treated wastewater discharge from the Fukushima No. 1 nuclear power plant, which began in late August, after extensive dialogue between the member states and Japan.