Rockhopper rocked by Argentine threats over Falklands oil
British oil and gas company Rockhopper Exploration saw its shares fall 6.4% following threats from Argentine president Javier Milei to impose sanctions on firms drilling for oil in waters off the Falkland Islands.
Milei warned that Argentina would reclaim the British territory and described the Sea Lion oilfield, owned by Rockhopper and Israeli partner Navitas Petroleum, as a 'clear and present danger'. The president stated that swift action was necessary, warning that within months the companies would gain access to oil beneath what Argentina considers its territorial waters.
The Sea Lion field, discovered by Rockhopper in 2010, was the first commercially viable oil discovery in the North Falkland Basin. After years of delays, Rockhopper and Navitas reached their final investment decision on the project in December 2025, having previously missed target dates in 2016, 2017, 2018, 2023-24 and 2024.
The field is estimated to contain between 500 million and 917 million barrels of recoverable oil. Phase 1 of the development targets 170 million barrels at a peak production rate of 50,000 barrels per day. The project requires $1.8 billion in funding to reach first oil and $2.1 billion to full completion, including contingencies and financing costs.
Economic stakes for the Falklands
The Sea Lion project represents enormous economic potential for the Falkland Islands. The development is projected to generate £4 billion in revenue for the territory over the next 35 years, which would equate to approximately £1 million for each of the islands' 3,700 residents.
Navitas Petroleum, which acquired operatorship and a 65% stake in the field from Harbour Energy in 2022, brings significant offshore experience to the project. The Israeli energy company has operatorship of the Shenandoah deepwater project in the Gulf of Mexico, which came onstream in early 2025. Rockhopper retained a 35% working interest in Sea Lion.
Despite the latest threats from Buenos Aires, both Rockhopper and Navitas insisted that Milei's statements would have no 'material effect' on their plans. The companies are due to begin extracting oil within two years.
Long-standing sovereignty dispute
The current tensions are rooted in a sovereignty dispute stretching back nearly two centuries. Britain has held possession of the Falkland Islands since 1833, while Argentina has maintained claims to the territory dating to its independence from Spain in 1816.
The dispute culminated in the 1982 Falklands War, a 74-day conflict that lasted from 2 April to 14 June and resulted in approximately 649 Argentine military deaths and 255 British military deaths. Britain retained control of the islands following the conflict.
In a 2013 referendum, Falkland Islands residents voted overwhelmingly to remain a British Overseas Territory, with approximately 4,000 islanders participating in the vote. London frequently cites this referendum when responding to questions over the islands' sovereignty.
Rockhopper shares, which take their name from the rockhopper penguins native to the Falklands region, closed down following Milei's comments. The development of the Sea Lion field remains a key strategic priority for both companies despite the renewed diplomatic tensions.