Pacific leaders are still on the fence about proposed plans to release treated nuclear wastewater into the Pacific - with Japan set to announce its final sign-off and start date as early as Tuesday.
The past, present and future Pacific Islands Forum (PIF) chairs - known as Troika - have not decided if they are for or against the imminent discharge.
The Melanesian Spearhead Group (MSG) has been urged at its meeting in Port Vila this week urging Japan not to go through with the release.
Vanuatu's Foreign Minister Matai Seremaiah said Japan's plans to release the treated wastewater from the destroyed Fukushima power plant site needed robust actions.
"[We are] urging polluters not to discharge the treated water in the Pacific Ocean until and unless the treated water is incontrovertibly proven to be safe to do so, and [to] seriously consider other options," he said.
This is contrary to former PIF chair and Fiji Prime Minister Sitiveni Rabuka, who said he is satisfied Japan's plan is safe after reading the UN nuclear agency's report.
Rabuka apologised to his Troika counterparts for going out on his own and backing the plans prior to the Troika meeting.
The concerns have gone back and forth for months, but the International Atomic Energy Agency said the discharge plan meets relevant international standards.
The Japanese Prime Minister Fumio Kishida is expected to make a final decision on Tuesday, after recently visiting the site.
Japan's state broadcaster, NHK, reports the government is aiming to start discharging the water as early as Thursday.
Kishida said he saw some progress in the understanding of the plan by Japan's fishing industry.
He made the comment after meeting with Sakamoto Masanobu, the head of the National Federation of Fisheries Co-operative Associations, and other representatives on Monday.
But Masanobu said he remains opposed to the release of treated water, as the plan has not won public approval.