Argentina's President, Javier Milei, has heightened tensions with the UK over the Falklands, warning he will impose economic sanctions on firms which exploit oil close to the British overseas territory.
In a national address, Milei said the "winds of change" favoured Argentina's claim to the islands, emboldened by signs the US might reconsider its stance of neutrality on the issue.
Milei said the Sea Lion oilfield, where a British and an Israeli firm are due to begin exploration work, was a "clear and present danger".
More than 40 years after the war over the territory, sovereignty of the archipelago in the south-west Atlantic Ocean remains hotly disputed between Britain and Argentina.
BBC News is seeking comment from the UK government on Milei's statement. It reiterated this week that Falkland islanders "are British with a right to determine their own future".
Milei announced his sanctions plan surrounded by his cabinet at the presidential palace, reiterating that the Falklands were "historically and legally" Argentinean.
The crux was a proposal to introduce a bill to parliament to impose sanctions on energy firms planning to begin oil exploration off the Falklands.
The Sea Lion oilfield, around 130 miles from the islands, contains an estimated 1.7 billion barrels of oil.
Two oil companies – Britain's Rockhopper Exploration and Israel's Navitas Petroleum – are due to begin extracting oil in the Sea Lion oilfield off the Falklands coast within two years, something Milei said Argentina could not allow.
Rockhopper has described the field as containing "highly marketable crude".
In a video posted earlier this year, Navitas highlighted the work it is already carrying out in the Falklands including building a dock, a heliport and accommodation for oil workers.
The BBC has contacted the two companies for responses to Milei's latest comments.
"If we do not act swiftly in a few months, they will have the material capacity to access the oil that lies underneath our sea – something that has never happened before," Milei said.
It is not yet clear how or to what extent the sanctions will be imposed or tightened. In Argentina, a current law already allows for restrictions of activities of oil companies participating in projects considered unauthorised on the islands.
In a 2013 referendum, residents of the islands voted overwhelmingly to remain a British overseas territory – with 99.8% voting in favour and just three voting against.
