Argentina on Friday defended its decision to take legal action against companies exploring for oil off the Falkland Islands, the latest twist in a tense sovereignty dispute with Britain.

Last week, the Argentine government said it had launched legal proceedings against three British firms -- Rockhopper Exploration, Premier Oil and Falkland Oil and Gas Limited -- and two from the US, Noble Energy and Edison International.

"Argentina will use the full force of national and international law to prevent Argentine resources from being exploited," Argentina's Secretary for the Malvinas Daniel Filmus told a press conference at the London ambassador's residence.

Britain and Argentina fought a 74-day war over the Falklands in 1982 which killed 649 Argentine troops, 255 British service personnel and three islanders.

Argentina claims it inherited the remote South Atlantic islands, which it calls the Malvinas, from Spain when it gained independence.

But Britain argues it has historically ruled them and that the islanders should have the right to self-determination.

Britain's Foreign Secretary Philip Hammond accused Argentina of "bullying" by taking legal action Friday.
"It is an outrageous piece of bullying and threatening against the Falkland Islanders' perfect right to develop their own economic resources," Hammond told Sky News television.

"Argentina needs to stop this kind of behaviour and start acting like a responsible member of the international community."

Filmus and Argentina's ambassador to London, Alicia Castro, said they were shocked by British Defence Secretary Michael Fallon's claim last month that Argentina posed a threat to the archipelago.

Fallon announced that the Falklands' military defences would be boosted with a £180-million ($268-million, 245-million euro) programme over 10 years in response to the "continuous intimidation" from Argentina.

"Whoever says that Argentina is posing a threat to the inhabitants of the Malvinas Islands is lying," Castro said.