Argentina's president has threatened to launch a legal challenge against the British government unless it halts oil exploration off the coast of the Falkland Islands.

In a social media post, President Javier Milei set a two-week deadline for the Sea Lion oilfield project to be scrapped. The project is a joint venture between Israeli and British companies, which insist they hold valid licences issued by Britain.

Milei said that if the deadline was not met, he had "instructed the Foreign Ministry and legal teams to initiate international arbitration" against the UK over what he called "the illegal plundering of our resources through the Sea Lion Project."

He warned that if the "illegitimate exploitation" of the region did not end within two weeks, Argentina would take the matter before the International Tribunal for the Law of the Sea, an independent judicial body based in Hamburg responsible for the application of the United Nations Convention on the Law of the Sea.

The move heightens tensions between the UK and Argentina over the sovereignty of the archipelago, known in Argentina as Las Malvinas, more than 40 years after a British military task force ejected Argentine forces that had invaded the territory in 1982.

The threat follows remarks Milei made at the UN General Assembly, where he criticised the organisation for failing to act on the sovereignty dispute. He said the UN had become "a useless organisation" which only serves "arrogant parasites dressed up as well-intentioned bureaucrats."

In response, UK Defence Secretary Wes Streeting said that Argentina "lacks the ability" to seize the Falklands by force.