Argentina and Britain have a longstanding foreign policy conflict over the sovereignty of the British-run islands, where they fought a brief war in 1982.
"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," Cameron said in a statement.
The South American nation has sought to revive negotiations over Falklands sovereignty, but Britain has said that was not on the table as long as the islands' inhabitants wanted to remain British.
The foreign ministry said Cameron would pay his respects to British personnel who lost their lives during the 1982 conflict and thank British military personnel serving on the Islands.
Cameron is expected to then visit Paraguay and attend the G20 Foreign Ministers meeting in Brazil.
(Reporting by Farouq Suleiman; Editing by Sharon Singleton)
