A spat broke out between Britain and Argentina at a nuclear security summit in Seoul on Tuesday when Argentine Foreign Minister Hector Timerman accused an extra-regional power of sending a submarine capable of carrying nuclear weapons to the South Atlantic.

Tensions between Britain and Argentina have risen as the 30th anniversary approaches of Argentina's invasion of the Falkland Islands in the far South Atlantic that was repulsed by a British task force after a 10-week conflict that killed 650 Argentine and 255 British troops.

Britain took Timerman's accusation personally, prompting Deputy Prime Minister Nick Clegg to rewrite his speech at the summit and open with a denial.

I'm afraid I'm duty bound to respond to the insinuations made by the Argentinean delegation of militarisation of the South Atlantic by the British Government, he said.

These are unfounded, baseless insinuations.

London has refused to start talks on sovereignty over the Falklands unless the 3,000 islanders call for them, which they show no signs of doing.

Argentina complained to the United Nations in February over what it called Britain's militarisation of the South Atlantic after London announced plans to dispatch a Navy destroyer to the area and it criticised the posting of Prince William - second-in-line to the British throne - to the islands as a military search-and-rescue pilot.

(Writing by Nick Macfie; Editing by Ed Lane)