Some British naval vessels were sent to fight the 1982 Falklands War carrying nuclear weapons, it has been confirmed.
The MoD has not said if HMS Sheffield was carrying nuclear arms
The Ministry of Defence said a decision not to use the weapons was made before the ships left port.
However, they were kept on board so the battle group could set sail from the UK as quickly as possible.
Rumours the weapons were on board Royal Navy ships first surfaced after the war with Argentina ended, but until now they have never been verified.
In fact the weapons never reached the combat zone as they were removed on the journey and transferred to ships returning to the UK.
Seven containers carrying the weapons were lightly damaged when transferred from ship to ship, the ministry said.
Argentina invaded the British territory of the Falkland Islands in the south Atlantic on 2 April 1982.
In response, Britain sent a number of warships, many of which routinely carried nuclear weapons at the time.
2 April: Argentina invades
5 April: Task force leaves UK
19 April: US diplomatic efforts fail
22 April: Royal Navy ships arrive in waters off Falklands
25 April: UK forces re-take island of South Georgia
3 May: Argentine cruiser General Belgrano sunk
4 May: HMS Sheffield sunk
21 May: British forces land on Falklands
28 May: Battle of Goose Green
13 June: British forces take Mount Tumbledown outside the capital, Stanley
14 June: Argentine garrison surrenders
The MoD spokesman said removing the weapons was a 36-hour operation, a delay that would have held up the task force for too long.
Reuters news agency quoted a Ministry of Defence (MoD) spokesman as saying the weapons never entered the territorial waters of the Falkland Islands or any South American country.
The Argentinean Defence Minister, Josť Pampuro, has expressed concern over the admission and said his country was seeking further information from the British Government.
An MoD spokesman told BBC News Online the admission was made "at the request of a journalist under an 'open government' code of practice".