Britain and Argentina continued to lock horns over the Falkland Islands amid rising tensions about oil exploration.
Sir Mark Lyall Grant, UK permanent representative to the United Nations, last night insisted there was "no doubt" about British sovereignty over the islands as Argentina's foreign minister asked for UN help in resolving the dispute.
Jorge Taiana told reporters after the meeting with Secretary General Ban Ki-moon that the UN chief was not happy to learn that the situation was worsening and was willing to continue his "good offices" mission.
Sir Mark said: "As British ministers have made clear, the UK has no doubt about its sovereignty over the Falkland Islands, South Georgia and the Sandwich Islands.
"This position is underpinned by the principle of self-determination as set out in the UN Charter.
"We are also clear that the Falkland Islands Government is entitled to develop a hydrocarbons industry within its waters, and we support this legitimate business in Falklands' territory."
The dispute stemmed from Britain allowing Desire Petroleum's Ocean Guardian to begin drilling 60 miles north of the islands after Argentina announced new shipping controls.
Defence Minister Bill Rammell said the Government would take "whatever steps are necessary" to protect the islands, which had a "legitimate right" to develop an oil industry within their waters.
Ocean Guardian was towed 8,000 miles from Scotland to the south Atlantic isles for the exploration.
Argentina formally objected to the move and tightened shipping regulations in the region.
Latin American and Caribbean nations backed Argentina's claim of sovereignty to the islands as the dispute gathered pace.
At the Rio Group summit of 32 countries hosted by Mexico, Argentina presented a statement quoting Mexican President Felipe Calderon as saying that "the heads of state represented here reaffirm their support for the legitimate rights of the republic of Argentina in the sovereignty dispute with Great Britain".
Argentinian president Cristina Fernandez ruled out any plans to try to keep the British boats or rigs out. "We do not believe in methods like blockades," she told reporters.
However in a statement to regional leaders in Cancun, Mexico she reiterated Argentina's claim to the islands and blamed the Foreign Office for fanning tensions.
Desire said the well is being drilled to an estimated target depth of about 3,500 metres (11,500 feet), and drilling operations are expected to take about 30 days.
The company said the rig is sitting "firmly inside UK waters".
Argentina claims the Falklands - known as Las Malvinas in Buenos Aires - are occupied by Britain illegally.
Argentina invaded the Falklands in 1982, before a UK taskforce made up of some 100 ships seized them back in a war which claimed the lives of 255 British servicemen and women and more than 600 Argentinians.