Argentina has accused Britain of provocative behaviour by planning to carry out military exercises in the Falkland Islands next week.
Deputy foreign minister Eduardo Zuain summoned the British Ambassador in Buenos Aires to protest over the "new show of military force".
It is the latest diplomatic clash following heightened tensions over the territory since Cristina Fernandez de Kirchner took power in Argentina.
A spokesman for the Embassy of Argentina in London said: "The Government of the United Kingdom will conduct military exercises on occupied Argentine territory between 14 and 27 April, including missile launchings from the Malvinas Islands.
"This action falls within a pattern already denounced by President Cristina Fernandez de Kirchner on 2 April, consisting of provocations and hostile acts towards Argentina from an extra-continental nuclear power.
"Deputy foreign minister Eduardo Zuain has summoned the British Ambassador in Buenos Aires to hand him a letter of protest in view of this new show of military force in the South Atlantic, a zone of peace.
"This action is a new example of UK's disregard for United Nations resolutions, which call on both parties to resume negotiations over sovereignty and refrain from introducing unilateral modifications in the situation as long as the dispute persists."
Islanders voted by 1,513 to three in favour of remaining British in a referendum last year, which Prime Minister David Cameron said "could not have sent a clearer message".