The simmering tension between Britain and Argentina over Falkland Islands threatened to escalate into an international crisis on Tuesday after Argentine President Cristina Fernandez de Kirchner announced that she intended to make a formal complaint to the United Nations about British “militarisation” of the region while Britain curtly rejected any negotiations over its territorial claims.

UK warns of Falklands blockade by Argentina (PDF)

Both countries claim sovereignty over the islands and went to war in 1982.

The Argentine move came as Britain planned to deploy one of its most modern Navy ships, HMS Dauntless, to the South Atlantic, off the Falklands, and Prince William arrived on the islands take up his assignment as a search-and-rescue helicopter pilot in a move that Argentina saw as a provocation on the eve of the 30th anniversary of British victory in the Falklands war that became the defining moment of Margaret Thatcher's controversial prime ministership.

While Britain described the deployment of HMS Dauntless and Prince Williams' posting as “entirely routine”, Ms. Fernandez accused it of “militarising” the region and threatening peace and security.

“We will present a complaint to the U.N. Security Council and the U.N. General Assembly, as this militarisation poses a grave danger to international security…We cannot interpret in any other way the deployment of an ultra-modern destroyer accompanying the heir to the throne, who we would prefer to see in civilian attire,” she told a meeting of MPs, senior officials, and veterans of the 1982 war.

Ms. Fernandez urged Prime Minister David Cameron to “give peace a chance” criticising his recent remarks in which he accused her administration of “colonialism”.

Argentina, which calls the islands Las Malvinas, has the backing of its regional allies including Brazil, Chile and Uruguay. In a show of solidarity, the South American trading bloc, Mercosur, has already closed its ports to ships flying the Falkland Islands flag.

Downing Street rejected the Argentine charge saying Britain was “not militarising the South Atlantic”.

British Foreign Office said the people of the Falkland Islands were “British out of choice”.

“They are free to determine their own future and there will be no negotiations with Argentina over sovereignty unless the islanders wish it,” it said.

The islands held by Britain since 1833 have a population of just 3,000.

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