The Governor of Papua New Guinea's New Ireland province says seabed mining is a risk not worth taking.
Sir Julius Chan remains opposed to the Solwara 1 project in which Canadian company Nautilus Minerals has a license to mine the Bismarck Sea for copper and gold.
Nautilus claims the project will cause little environmental damage.
But there's growing opposition to the world's first major deep sea mining operation, with environmentalists warning that too much is unknown about the impacts.
Sir Julius says there's no need for New Ireland to allow its all important marine environment to be put at risk.
"We've got enough resources now to probably take us through the next two decades and we can afford the time to sit back and watch this exploratory work underwater taking place and in a much more controlled environment than in our waters."
Sir Julius Chan.