What is there to negotiate? The Falklands are British territory...end of story.
Yes, but a deal with Argentina on exploitation of any oil resources could defuse some tensions, and also makes some sense given geographic realities - it would be advantageous to be able to use Argentinian ports. There are matters than can be negotiated in good faith, without the sovereignty of the Falkland Islands being on the table.
There are also issues relating to potential disputes over the Antarctic Treaty that would best be avoided. That is completely separate to the Falklands issue.