Argentina has renewed its claim over the Falkland Islands on the 25th anniversary of invading them - and losing a subsequent war with Britain.
"The Malvinas are Argentine, they always were, they always will be," said Argentine Vice-President Daniel Scioli, using the Spanish name for the islands.
Mr Scioli was speaking in the southern city of Ushuaia - one of a series of events marking the start of the war.
He urged the UK to resume talks on the sovereignty of the islands.
In the UK, Prime Minister Tony Blair presented the ex-servicemen - from the Scots Guards and Royal Navy - with veterans' badges and certificates to honour their "courage and professionalism".
More than 900 people died in the 74-day war, including 255 British servicemen, 655 Argentines and three islanders.
A UK military task force sailed for the Falklands in April 1982, and troops began a campaign to regain the islands by the end of the month.
Several major land and sea battles followed before the British eventually broke Argentine resistance, recapturing control of Stanley, the islands' capital, on 14 June.
'We will return'
Argentina continues to claim sovereignty over the islands, which it has done since 1833.
President Nestor Kirchner did not attend the main ceremony in Ushuaia, where one resident climbed on a mound of dirt and planted his own Argentine flag, with a drawing of the islands and the words: "We will return."
Addressing the veterans there, the Argentine vice-president said Argentina would never again resort to force.
"Once again, we urge the United Kingdom to heed international calls and resume negotiations in the appropriate manner, through the United Nations," Mr Scioli told the crowd.
"Too much blood was spilled and that should never be repeated," said the head of the armed forces, Jorge Chevalier.
Most in Argentina now regard the invasion, ordered by the country's ruling military dictatorship, as a mistake, says the BBC's Daniel Schweimler in Buenos Aires.
In London, former UK Prime Minister Margaret Thatcher, who sent troops to recapture the islands, attended a private memorial ceremony in St Paul's Cathedral.
The build-up to the anniversary has been marked by tensions between Argentina and the UK.
Last week Argentina unilaterally scrapped an oil and gas exploration treaty with the UK.