Argentina’s government has given the United Kingdom two weeks to halt activity linked to the Sea Lion offshore oil project, escalating Buenos Aires’ long-running dispute with London over the Falkland/Malvinas Islands.

President Javier Milei has instructed the Foreign Ministry and government lawyers to begin international arbitration under the UN Convention on the Law of the Sea, according to Argentina’s presidency. The stated aim is to stop what Buenos Aires calls the unlawful exploitation of hydrocarbons in the North Malvinas Basin.¹

Argentina says Sea Lion — a project involving Britain’s Rockhopper and Israel’s Navitas and expected to begin production in 2028 — lies on its continental shelf. Milei framed the dispute in uncompromising terms, writing that Argentina would seek action at the International Tribunal for the Law of the Sea if Britain did not stop the “illegitimate exploration” within two weeks. “The Malvinas are Argentine, and that is defended with facts, not words,” he said.²

The government’s approach combines legal pressure with wider measures. It has pursued sanctions related to natural-resource activity around the islands, raised objections with British and Israeli representatives, and announced plans for an integrated naval base in Tierra del Fuego. Argentina also initiated proceedings involving Thales UK over operations on the islands’ air link to Punta Arenas, Chile.¹

London, however, rejects Argentina’s claimed jurisdiction over the territory, which Britain has administered since 1833. Its response, as reported in Argentina, is that island residents have the right to exploit their natural resources and that the companies involved have British support.²

Both accounts place the oil dispute within the unresolved sovereignty conflict, which led to the 1982 war. Argentina argues that UN recognition of a sovereignty dispute means unilateral resource decisions should be avoided; Britain’s position instead reflects its control of the islands and the authority it attributes to their residents.²