Argentina Threatens Tribunal Action, Gives UK Two Weeks to Halt Falklands Oil Project

BUENOS AIRES — Argentina is threatening legal action against the United Kingdom if London does not halt an oil project off the Falkland Islands, escalating a long-running sovereignty dispute in the South Atlantic.

President Javier Milei said in a statement published on X that Britain had two weeks to stop work on the Sea Lion project. If it does not, Argentina would ask the Hamburg-based International Tribunal for the Law of the Sea to order a temporary halt to the project, he said.

The Sea Lion project is operating in the North Falkland Basin under British licenses. Argentina rejects those licenses as illegitimate and regards the islands—known in Argentina as the Islas Malvinas—as part of its territory.

The archipelago has been a British Overseas Territory since 1833. Buenos Aires bases its claim on legal succession from the former Spanish colonial empire, while London has long defended its sovereignty over the islands and surrounding waters.

The dispute erupted into war in 1982, after Argentina's ruling military junta ordered the occupation of the islands. Then-British Prime Minister Margaret Thatcher dispatched thousands of troops aboard dozens of warships. British forces recaptured the islands within 11 weeks, and hundreds of soldiers were killed.

The new warning could complicate relations between London and Buenos Aires and add uncertainty to energy development around the Falklands. It also highlights how competing claims over maritime jurisdiction can turn oil and gas projects into flashpoints far beyond the immediate commercial stakes.

With the two-week deadline now running, the next phase may hinge on whether Britain treats the threat as a negotiating lever or a legal challenge that must be answered in international court.