阿根廷威胁福克兰群岛的英国石油勘探者

Argentina has threatened to retaliate against a UK energy company because of its plans to drill a giant new oil field close to the Falkland Islands.

Rockhopper Exploration and Israeli business Navitas plan to start drilling the Sea Lion offshore deposit north of the Falklands within months, potentially sending oil back to Europe and the UK from early 2028.

However, the scheme has infuriated Argentina, which claims sovereignty over the seas around the islands.

Its London embassy this week declared Rockhopper’s plans “unlawful”, warning Argentina now considered Rockhopper and Navitas to be “clandestine” – or illegal – companies.

“Hydrocarbon exploration or exploitation activities in the disputed areas constitutes an unlawful act under both international law and the Argentine legal system,” the embassy said. “The Argentine Republic … reserves the right to fully exercise all available actions to safeguard its sovereign rights and interests.”

It follows Rockhopper’s latest announcement that it is moving Sea Lion from exploration into development, upgrading the volumes of recoverable oil – which could total more than a billion barrels.

This makes it several times larger than Rosebank, the largest known remaining field in UK waters.

Britain and Argentina fought a short but intense war for the Falklands when Argentine forces seized the islands in 1982.

They were forced into a humiliating surrender by a British expeditionary force, but Argentina has never relinquished its claims over the islands, which it knows as the Islas Malvinas.

The recent discovery of significant oil resources near the islands has reopened the dispute, with tensions heightening as development gets closer. Sea Lion is thought to be just one of several huge new oil fields around the Falklands.

Sam Moody, Rockhopper’s chief executive, confirmed this week that the company had received “sanction” – or approval – for the project and was funded for its first stage of development.

He told investors that development work was underway in the Falklands with first drilling planned for early 2027 and oil production a year later.

An oil production and storage ship, the Aoka Mizu, has been redeployed from the North Sea and is now being fitted out for its new task. There are also plans for a second, much larger ship to accelerate development.

The latest clash followed a speech by Javier Milei, the Argentine president, on “Malvinas Day” in April, when he warned that his government “will respond with all necessary diplomatic measures” to protect the country’s interests in the face of the advancing Sea Lion oil project.

“We act with determination against unilateral and illegitimate activities that seek to exploit resources belonging to the Argentine people,” he said.

Mr Milei has separately announced plans for a major increase in military expenditure including buying two dozen F-16 fighter jets from Denmark.

He has said he plans only diplomatic pressure for the Falklands. Argentina is undergoing a rapid expansion in oil production after discovery and exploitation of the massive Vaca Muerta inland shale oil deposits.

Several British companies including Shell, BP and Harbour Energy are leading the way in Vaca Muerta, with current output of 800,000 barrels a day expected to double within a few years, making Argentina a major player in global energy supplies.

However, there are fears Argentina could sideline them if Rockhopper and Navitas continue with the Sea Lion plan.

The Sea Lion field was originally discovered by Rockhopper, but the cost of development prompted it to go into partnership with Navitas, which now holds two thirds of the working interest in the project.

Dan Slater, an analyst at Zeus Capital, described the oil field as a “huge, world class discovery” with further potential exploration sites to the south of the islands.

The moves to exploit the natural resources come as Ed Miliband, Britain’s Energy Secretary, bans exploration in UK waters.

He is due to make a decision on the controversial Rosebank oil field and Jackdaw gas field imminently. In opposition, he condemned such developments as “climate vandalism”.

However, the Falklands are a British overseas territory that governs itself and as a result, Mr Miliband’s ban does not apply there.

A Foreign Office spokesman said the Falkland islanders had jurisdiction over their own oil and gas developments.

The spokesman said: “Any decision regarding Sea Lion is for the Falkland Islands government and the private companies concerned.

“The UK is unwavering about our sovereignty over the Falkland Islands and our support for the Falkland Islanders’ right of self-determination.”