Argentine foreign ministry officials say they will prosecute oil companies operating near the Falkand Islands known as Las Malvinas in South America.
Falklands War Veterans in Buenos Aires remember their fallen comrades in a midnight vigil on 1 April. Photo: AFP
The officials said companies active there were operating illegally in Argentine territory.
The announcement came as Argentina marked the 33rd anniversary of the war with the UK over the islands.
Earlier this week, three British oil exploration companies announced new oil and gas finds north of the islands.
In a speech in the city of Ushuaia the Argentine president, Cristina Fernandez de Kirchner said Argentina had always been a victim of colonialism, "Our land has always been invaded, first by the Spanish, then by the English. "
A long-running dispute over the islands has created fresh tensions recently.
In March, the Argentine Foreign Ministry protested when the British Defence Secretary, Michael Fallon announced Britain would spend £280m over the next 10 years on renewing and improving defences on the islands.
The money, he said, would be spent on improving communications systems and replacing the Rapier air defence missiles when they go out of service at the end of the decade.
He also said the British government would invest in harbour facilities and fuel infrastructure.
Mr Fallon said the government was committed to protecting the Falkland islanders "right to remain British"
President Fernandez de Kirchner said in her speech that the British government was "confusing the people with government business in order to satisfy the armament manufacturers lobby and to win elections."
Her speech comes days after the Argentine Secretary for Malvinas Island Affairs, Daniel Filmus announced that new legislation passed in 2013 would be used to prosecute foreign oil companies breaking Argentine law by prospecting or extracting oil in the country's territory.
The law establishes that foreign oil companies executives face up to 15 years in prison and heavy fines, if they do not have Argentine government permission to carry out their work.
The British government rejected the law, arguing it could not be applied to the zone around the Falkland islands over which Britain had legal ownership.
At the end of February, Argentine officials in Ushuaia reported the arrival of a new oil exploration platform owned by British exploration companies, Rockhopper, Falkland Oil and Gas, Premier Oil and Noble Energy.
Earlier this week, three of the companies announced an oil discovery to the north of the Falkland islands - the first in a nine-month drilling campaign.
- BBC
