Argentine President Javier Milei has given the United Kingdom two weeks to halt work on the Sea Lion oil project near the disputed Falkland Islands or face an international legal challenge.
Buenos Aires claims sovereignty over the British-administered archipelago, known in Argentina as Las Malvinas, while Britain rejects that claim and says islanders have the right to determine their future and develop local resources.
Milei said Argentina would take the dispute to the International Tribunal for the Law of the Sea if work on Sea Lion did not stop within the deadline.
He said he had instructed the Foreign Ministry and legal teams to begin international proceedings against the UK over the project.
The tribunal, an independent judicial body based in Hamburg and established under the United Nations Convention on the Law of the Sea, can issue legally binding emergency orders, though it has no mechanism to force a government to comply.
Argentina has already pursued legal action over the British-authorised project, arguing that it violates a UN resolution calling on both sides to avoid unilateral actions concerning the islands while the sovereignty dispute remains unresolved.
Milei has previously described Sea Lion as a “clear and present danger”.
Sea Lion lies about 130 miles, or 209 kilometres, from the Falkland Islands and is estimated to contain 1.7 billion barrels of oil.
Britain’s Rockhopper Exploration and Israel’s Navitas Petroleum are expected to begin extraction within two years and have maintained that they hold valid licences issued by the Falkland Islands authorities.
The British government has said it supports businesses operating near the islands.
The dispute adds to longstanding tensions over the archipelago.
In a 2013 referendum, 99.8% of island residents voted to remain a British overseas territory, while Argentina maintains that the islands were populated illegally.
The sovereignty dispute led to a 74-day war in 1982 after Argentine forces invaded the islands and were later expelled by a British military task force.
The conflict killed 649 Argentine military personnel, 255 British military personnel and three islanders.