The sovereignty of the Falkland Islands will not be up for discussion as long as they want to remain a British territory, Lord Cameron has said.
The foreign secretary is preparing to make the first visit to the islands by a cabinet minister since 2016.
Last month Argentina's President Javier Milei called for the islands in the South Atlantic Ocean to be handed over.
The trip comes ahead of a summit of the foreign ministers of the G20 countries, which include Argentina and the UK.
Lord Cameron reiterated the UK government's longstanding position the islands' sovereignty is non-negotiable while its residents wish it to be British.
Speaking ahead of the trip, he said: "The Falkland Islands are a valued part of the British family, and we are clear that as long as they want to remain part of the family, the issue of sovereignty will not be up for discussion.
"The Falkland Islanders should be proud of the modern, prosperous community they have built."
The foreign secretary's visit is against a backdrop of continued calls by Argentina for the self-governed territory to be handed to Buenos Aires.
After his meeting with President Milei last month, who believes his country has non-negotiable sovereignty over the islands Argentina calls Islas Malvinas, the Foreign Office said "they would agree to disagree, and do so politely".
The islands, 8,000 miles from the UK and 300 miles off the coast of Argentina, were the subject of war in 1982 claiming the lives of 255 British servicemen, three islanders and 649 Argentinian personnel.
In 2013, when Lord Cameron was prime minister, islanders voted in a 90% turnout referendum in which 1,513 were in favour of remaining a UK overseas territory while just three votes were against.
Mr Milei has previously suggested a Hong-Kong style handover and has stressed war "is not a solution".
Falklands sovereignty not up for debate, says Sunak
A profile of the Falkland Islands
During his visit, Lord Cameron is expected to pay his respects to those who lost their lives during the conflict, meet leaders of the Falkland Islands government in a visit to capital Stanley, as well as greet the Islands' penguins.
The last cabinet minister to visit the islands was then-Defence Secretary Michael Fallon in 2016.
Lord Cameron is then set to visit Paraguay - the first time a British foreign secretary has visited the South American nation.
Afterwards he will attend a meeting of G20 nations - including Russia's Sergei Lavrov - in Brazil on Wednesday.
