Argentina has lodged a protest with the UK over London's plans to begin offshore oil exploration off the north coast of the disputed Falkland Islands.
Jorge Taiana, the Argentinian foreign minister, said that Argentina "firmly rejects" the UK's plans to authorise oil and gas exploration "in the Argentine continental shelf area".
"We will do everything necessary to defend and preserve our rights," he said on Tuesday, following a meeting with British embassy officials in Buenos Aires.
Local media reported that Desire Petroleum, a British oil company, is soon to start exploration drilling off the coast of the Falkand Islands.
The islands, known as the Islas Malvinas in Spanish, have been under British control since 1833, but Buenos Aires considers them part of Argentine territory.
In 1982, Argentina and Britain fought a 74-day war over the islands in which almost 1,000 people were killed, and tensions over the islands continue to simmer.
Indications that there could be large oil reserves around the Falklands have raised the stakes in the sovereignty dispute.
Buenos Aires says that the UK continues to skirt UN resolutions calling on both governments to renew a dialogue on the sovereignty of the South Atlantic archipelago.
Britain last month rejected Argentina's latest claim to the islands.