Argentine President Javier Milei has said that his government would seek international arbitration against the United Kingdom over an oil project off the British-controlled Falkland Islands.

The move escalates a clash over resources that could transform the economy of the sparsely populated South Atlantic archipelago.

Milei’s office said it had given the UK two weeks to halt work on Sea Lion, an offshore oilfield being developed by Israel’s Navitas Petroleum and England’s Rockhopper Exploration. 

Otherwise, Argentina would ask the International Tribunal for the Law of the Sea, a Hamburg-based maritime court, to order a temporary halt to the project.

‘Argentina will not stand idly by,’ the presidential statement said, accusing the UK of causing ‘irreversible and irreparable’ harm.

The tribunal, an independent court established under the 1982 UN Convention on the Law of the Sea, can issue legally binding emergency orders. 

But even if it ordered the UK to halt the project, it has no means of forcing the government to comply.

The UK rejects Argentina’s sovereignty claim, arguing that the islanders have the right to determine their own future and develop their natural resources. 

Argentine President Javier Milei has said that his government would seek international arbitration against the United Kingdom over an oil project off the British-controlled Falkland Islands

In a referendum in 2013, residents of the Falklands voted overwhelmingly to remain a British overseas territory. Argentina says the islands were populated illegally. 

Foreign Minister Pablo Quirno praised Milei’s move as ‘a historic and unprecedented step’ in Argentina’s nearly two-century campaign to secure sovereignty over the archipelago.

‘Whoever explores or exploits our natural resources in the Malvinas without Argentine authorisation must face the consequences,’ he wrote on X, using Argentina’s name for the islands.

But critics accuse the Argentine president of using the sovereignty claim – one of the few causes in Argentina that cuts across the country’s stark political lines – to bolster flagging public support ahead of next year’s election as the economy falters. 

Milei, a self-described ‘anarcho-capitalist,’ initially drew scorn from his nationalist opponents for his conciliatory stance toward Britain and professed admiration for Margaret Thatcher, the wartime prime minister loathed in Argentina for ordering the islands’ recapture. 

The brief but bloody war, which erupted when the Argentine military dictatorship invaded the archipelago in 1982, killed 649 Argentine troops, 255 British service members and three islanders.

But Milei has taken an increasingly confrontational stance as oil production near the islands approaches its anticipated start in 2028 and US President Donald Trump, a close ally of the Argentine leader, suggests he could reconsider Washington’s long-standing neutrality in the dispute.

Last week, Milei dedicated much of his UN General Assembly speech to Argentina’s sovereignty claim, accusing the international body of neglecting the Falklands dispute and denouncing the oil project as an illegal exploitation of Argentine resources.

He has threatened sanctions that would bar companies drilling around the Falklands from operating in Argentina’s booming oil and mining sectors. 

His government has sent Congress a bill proposing prison terms of up to 20 years for extracting resources around the islands without Argentine authorisation and extending penalties to fishing, the bedrock of the islands’ economy. 

Argentine authorities say they are investigating at least 60 companies and executives for possible violations. 

An Argentine judge this month also ordered a halt to work on Sea Lion pending an environmental review.

This is a breaking news story. More to follow.