Argentina pledged to use diplomatic channels to protest British military exercises near the disputed Falkland Islands that have provoked new tensions between London and Buenos Aires.
"We are very concerned by this acceleration or provocation by the United Kingdom, but we are not going to fall for any provocation and we will not stray from the law, diplomacy and peace," Argentine Foreign Minister Hector Timerman told reporters.
He said Argentina had not been informed ahead of time about the British military exercises around the disputed territory, which Buenos Aires calls the Malvinas Islands.
The Foreign Office has said the exercises are "routine" and have "been carried out every six months for the last 28 years."
But Argentina on Saturday decried the maneuvers and military build-up as an "unacceptable provocation," and on Monday lodged a formal complaint with the United Nations in response.
The country's UN envoy Jorge Arguello told Argentine radio he had delivered a letter of protest to UN Secretary General Ban Ki-moon, a copy of which had been given to the British embassy in Buenos Aires.
President Cristina Kirchner has denounced the exercises as a "militarization of the South Atlantic" and warned that the maneuvers could spark an arms race in the region.
She posted several messages on the social networking site Twitter, including one describing the British moves as "typical 19th century colonialism."
On Tuesday, the twelve-member Union of South American Nations (UNASUR) issued a statement "expressing its most formal and energetic protest" against the British operation, "demanding the British government to abstain" from carrying them out.
The statement, issued in Quito -- Ecuador currently holds the group's rotating presidency -- adds that the regional group reiterates its "firm support for the legitimate rights" of Argentina over the archipelago, and the regional interest for a peaceful resolution to the dispute.
Around 3,000 people live on the barren South Atlantic islands, which lie 450 kilometers (280 miles) off the Argentine coast.
Britain has held the archipelago since 1833. In 1982, Argentina's military junta invaded, prompting a short but bloody war that left 649 Argentine troops and 255 British troops dead.
