Naura puts UN on two-year deadline to make deep-sea mining rules DeepGreen plans to extract cobalt and other battery metals from the seabed. ( Image courtesy of DeepGreen.) The small Pacific island nation of Nauru made waves this week when it notified a United Nations (UN) body of plans to start deep-sea mining, giving the International Seabed Authority (ISA) two years to complete long-running talks on rules governing the new and controversial industry. Nauru planned to trigger the “two-year rule”, which allows for a mining plan to be approved after two years under whatever rules are in place at that time.