Argentina's president accused Britain of "militarising the South Atlantic" and said she would to complain to the United Nations, as tension rises ahead of the 30th anniversary of the Falklands war.
Britain, which rejected the accusation, went to war with Argentina over the British-ruled Falkland Islands in 1982. London has refused to start talks on sovereignty with Argentina unless the roughly 3,000 islanders want them.
"They're militarising the South Atlantic once again," President Cristina Fernandez said in a speech on Tuesday at the presidential palace, criticising the deployment of British destroyer ‘HMS Dauntless’ in the area in the coming months.
"If there's one thing we're going to preserve, besides our natural resources, is a region where peace prevails," she said, adding that the Foreign Ministry would present a formal complaint to the U.N. Security Council and General Assembly.
She also criticised Prince William's posting as a military search-and-rescue pilot in the islands, called Las Malvinas in Spanish: "We would have liked to see him dressed as a civilian, not with a military uniform," she said.
A spokeswoman for British Prime Minister David Cameron on Wednesday rejected Fernandez's comments.
"We are not militarising the South Atlantic. Our defensive posture in the Falkland Islands remains unchanged," the spokeswoman said. The defence ministry has described the deployment of HMS Dauntless as "entirely routine".
"The people of the Falklands choose to be British. Their right to self-determination is a principle that's enshrined in the UN charter," she added.
A war of words between the two governments has escalated in recent months.
Fernandez, a fiery former senator who started her political career in the Patagonian region closest to the islands, has described Britain as a "crass colonial power in decline."
Cameron hit back by accusing Argentina of colonialism.
Oil exploration by British companies off the islands has raised the stakes over the sovereignty dispute.
Three decades on, memories of the war remain painful in Argentina, where most people see the decision by Argentina to invade the islands on April 2, 1982 as a mistake by the discredited military dictatorship ruling at the time.
Fernandez also signed a decree on Tuesday to declassify a military report that was commissioned in the aftermath of the 10-week conflict in which about 650 Argentine and 255 British troops were killed.