A UN report saying that the Falkland Islands lie within Argentina's maritime territory reopened old wounds in Britain and the South American nation as British Premier David Cameron dismissed the findings on Tuesday.
The UN Commission on the Limits of the Continental Shelf (CLCS) had approved a motion by Argentina to extend its waters in the South Atlantic Ocean by 35 per cent.
In a video message Monday, Argentinian Foreign Minister Susana Malcorra welcomed the CLCS decision on what she called a "politically, economically and strategically important area."
Malcorra called the ruling a "historic event" and a "significant move towards the drawing of Argentina's external borders." The new border would expand the area of Argentine sovereignty by 1.7 million square kilometres.
The British government on Tuesday dismissed the ruling as not binding.
"At this stage we have yet to receive details of that report. It is important to note that this is an advisory committee. It makes recommendations - they are not legally binding," Cameron's spokeswoman said, according to the Press Association.
The views of the local population had to be taken into account, she said: "What is important is what the Falkland islanders themselves think. They have been very clear that they want to remain an overseas territory of the UK, and we will continue to support their right to determine their own future."
According to the Press Association, the government of the Falkland Islands, known in South America as the Malvinas, was currently seeking clarification from London regarding the implications of the CLCS ruling for the islands.
In New York, Stephane Dujarric, a spokesman for UN Secretary General Ban Ki-moon, clarified the ruling Tuesday, saying that the commission "did not consider and qualify those parts of the submission that were subject to dispute ... in accordance with its rules and procedures."
The Falkland Islands, around 400 kilometres off the Argentinian coast, have been a crown colony of Britain since the 19th century, but Argentina has consistently claimed sovereignty over the Malvinas.
In 1982, the two countries were embroiled in a brief war, in which around 900 people were killed.
In a 2013 referendum, the inhabitants of the archipelago voted with an overwhelming majority to remain part of Britain.
According to British media reports, the ruling could have implications for the exploitation of natural resources, including oil and gas.