Argentina last night ramped up its diplomatic rhetoric over the Falklands, accusing the UK of deploying nuclear weapons near the islands.

Foreign Minister Hector Timerman made the claim as he urged the United Nations to intervene in the dispute.

He said it had intelligence that a Vanguard submarine was deployed in the area.

Speaking in New York, Mr Timerman said: "Thus far the UK refuses to say whether it is true or not. Are there nuclear weapons or are there not? The information Argentina has is that there are these nuclear weapons."

Mr Timerman accused Britain of using an "unjustified defence of self-determination" to maintain a military base on the Falklands, which allowed it to dominate the Atlantic.

"It is perhaps the last refuge of a declining empire," he said. "It is perhaps the last ocean that is controlled by the UK."

He said Britain had been "colonialist throughout [its] history", and should now "give peace a chance".

UN Secretary-General Ban Ki-moon issued a statement expressing "concern about the increasingly strong exchanges".

After holding talks with Mr Timerman, he said the international body would be happy to help mediate.

Britain's ambassador to the UN, Mark Lyall Grant, said the Government does "not comment on the disposition of nuclear weapons, submarines etc".

He said Argentina's accusation the UK was militarising the situation was "manifestly absurd".

"Before 1982 there was a minimal defence presence in the Falkland Islands," he said. "It is only because Argentina illegally invaded the Falkland Islands in 1982 that we had to increase our defence posture.

"Nothing has changed in that defence posture in recent months or years."

Mr Lyall Grant said the UK had been in the Falklands since before Argentina existed.

Prime Minister David Cameron and Argentine president Cristina Kirchner have been trading barbs for months.

The UK has insisted that the deployment of one of its most modern destroyers, HMS Dauntless, to the region is merely routine.

The Duke of Cambridge's arrival in the Falklands for a posting as an RAF search and rescue pilot caused fury in Argentina.