David Cameron, the British prime minister, has called Argentina's invasion of the Falkland Islands three decades ago a "profound wrong" aimed at depriving the islanders of their freedom.
Cameron's comments on Monday come as Britain and Argentina continue to trade accusations of "colonialism" in a renewed war of words over the South Atlantic archipelago.
Cameron also reaffirmed Britain's commitment to defending the islanders' right to choose their fate in a statement issued on Monday to mark the war's 30th anniversary.
"Thirty years ago today the people of the Falkland Islands suffered an act of aggression that sought to rob them of their freedom and their way of life," Cameron said.
Britons were "rightly proud of the role Britain played in righting a profound wrong", Cameron said.
Ceremonies will be held both in Argentina and Port Stanley in Falkland Islands on Monday to mark the anniversary of the start of the war.
Cristina Fernandez Kirchner, the Argentine president, a centre-leftist who hails from the chilly Patagonian region closest to the Falklands, has condemned "the plundering of our natural resources, our oil”.
The discovery of oil off the Falklands has raised the stakes, leading Argentina to threaten to sue companies involved in oil exploration and to protest to the UN over British "militarisation" of the South Atlantic.
On April 2, 1982, the then-ruling military junta in Argentina invaded the Falklands, igniting a 74-day war with Britain that cost the lives of 649 Argentine, 255 British troops and three Falkland islanders.
The war ended in defeat for Argentina, with Britain maintaining control over a territory it has ruled since 1833.
Argentina has claimed the territory - which it calls the Malvinas. The South American country says it inherited the islands from Spain on independence and that Britain expelled an Argentine population from the islands.
Argentine to sue banks
On Sunday, the eve of the 30th anniversary of the war, the Sunday Telegraph newspaper, reported Argentina had threatened legal action against British and US banks for advising firms hunting for oil off the Falkland Islands and writing reports on them.
As many as 15 banks have been sent warning letters by the Argentine embassy in London, including US giant Goldman Sachs, Credit Suisse and the London-based Barclays Capital and Royal Bank of Scotland.
They could face criminal and civil action in the Argentine courts.
The island's oil reserves, which remain untapped until now but which analysts predict could be worth tens of billions of dollars, have been a major source of tension between the countries since their discovery in 1998.
Buenos Aires has won support from regional bodies, and the Latin American trading bloc Mercosur has banned port visits by Falklands-flagged ships.
The UNASUR group of South American nations rejected British oil exploration around the Falklands in March, and Peru cancelled a visit by a Royal Navy frigate.
Latin American backing for Argentina could also deal a blow to British hopes of expanding trade with the continent.