Downing Street has rejected Argentine claims that Britain is creating a risk to international security by "militarising" the long-running dispute over the Falkland Islands.
President Cristina Fernandez de Kirchner has said Argentina will make a formal complaint to the United Nations over the UK's decision to send one of its most modern warships and the Duke of Cambridge to the South Atlantic.
But No 10 said the despatch of destroyer HMS Dauntless to the Falklands to replace the frigate HMS Montrose did not amount to an escalation of military activity.
"We are not militarising the South Atlantic," said a Downing Street spokeswoman.
"Our defensive posture in the Falklands remains the same."
The spokeswoman confirmed that the Government has contingency plans in case of aggressive actions towards the self-governing British overseas territory.
But she stressed that the contingency plans have been in place for some time, and are not a response to the recent spike in tension between London and Buenos Aires as the 30th anniversary of the war for the islands approaches.