Key facts
- Marcelo Kohen, representing Argentina, told the tribunal the UK cannot treat disputed waters as a "Dominium maris Britannici."
- Argentina asked Itlos to order Britain to suspend drilling in the North Basin pending further arbitration.
- Ellie Reeves, attorney general for England and Wales, said suspension would kill the Sea Lion project.
- Mario Oyarzábal said the question is whether the UK may authorize new drilling while the sovereignty dispute stands.
- The UK argued there is no urgency because extraction would not take place until 2028.
Argentina told an international tribunal in Hamburg that Britain should not be allowed to treat the waters around the Falkland Islands as a "Dominium maris Britannici," the historic doctrine of broad Crown sovereignty over the oceans. Marcelo Kohen, representing Argentina at the International Tribunal for the Law of the Sea, mocked the UK position on the second day of hearings, according to a report published November 11, 2026.
Argentina has asked the tribunal, known as Itlos, for a ruling that would force Britain to suspend drilling in the North Basin of the Falkland Islands ahead of further arbitration. The Sea Lion oil field lies around 130 miles north of the islands, a British overseas territory over which Argentina has a long-standing sovereignty claim.
Kohen said the sovereignty dispute did not turn the surrounding areas into a "legal black hole" where the UK could do as it wished with natural resources. He told the panel that exploitation of hydrocarbons would put the islands among the highest ranks of wealth just below the principality of Monaco while depriving Argentina of rights to those resources. He also said the UN regards the islands as a non-self-governing territory and called in 1976 for both sides to refrain from steps that would unilaterally change the situation before the dispute was settled.
Ellie Reeves, the attorney general for England and Wales, told the judges on Tuesday that Argentina was seeking to further its sovereignty ambitions through the suspension request. She said such a move would kill the Sea Lion project with "disastrous consequences" for the Falkland Islanders and the companies involved, and the UK argued the tribunal lacks jurisdiction over sovereignty matters.
Mario Oyarzábal, legal adviser to the Argentine ministry of foreign affairs, said in closing remarks to the panel of 20 judges that Argentina rejects the UK's attempt to frame the proceedings as sovereignty litigation. He said the question is narrower: whether, while the dispute remains unresolved, the UK may unilaterally authorize or carry out new drilling in the disputed maritime area.