The request came a day after the Foreign Office called in Argentina's ambassador to the UK when legal action was threatened against oil firms operating near the Falkland Islands.

Argentina has now launched charges against three UK companies.

The islands remain the subject of a sovereignty dispute with the UK.

The Foreign Office has confirmed British Ambassador John Freeman was summoned on Thursday.

It is understood Argentine Deputy Foreign Minister Eduardo Zuain demanded explanations over the "silence of the British government" following allegations made by US whistle-blower Edward Snowden.

'New defences'

Reports, published by online publication The Intercept earlier this month, suggested the UK conducted electronic surveillance on Argentina between 2006 and 2011 over concerns it would launch an attempt to reclaim the Falklands.

The two nations fought a war over the islands, known as the Malvinas in South America, in 1982.

According to an Argentine statement, Mr Zuain also expressed the government's unease at a statement made by the UK Defence Secretary Michael Fallon in the Commons last month.

Mr Fallon had told MPs that two Chinook helicopters and an upgraded surface-to-air missile system will be part of a new defence package.

The British government earlier protested to the Argentine ambassador in London about the legal threats and what it said were recent strong statements against the UK's sovereignty over the Falklands.

Argentina's president Cristina Fernandez de Kirchner and ambassador Alicia Castro last week launched new criticism of the government's plan to boost defences.

A Foreign Office spokesman said: "The UK has no doubt about its sovereignty over the Falkland Islands and surrounding maritime areas, nor about the Falkland Islanders' right to decide their own future.

"We object strongly to recent statements by the Argentine president and the Argentine ambassador to London and so summoned the ambassador to account for these."

In 2013, Falkland Islanders took part in a referendum, voting by 1,513 to three to remain a British overseas territory.