On the 30th anniversary of the end of the Falklands war, Argentina's president Cristina Fernandez de Kirchner will travel to the UN in New York to reassert her country's claim to sovereignty over the islands.
She will attend a usually low-key annual meeting of the UN's Decolonisation Committee , reportedly with around 90 delegates.
It is the first time a head of state has shown up in person.
The UK refuses to participate in the 29-country committee, but two of the Falkland Islands' four legislative assembly members, Roger Edwards and Mike Summers, will be there to speak.
Mr Edwards told Sky News Online: "My message to President Cristina Fernandez and the government of Argentina is that we, the people of the Falkland Islands, have a right to determine our own future.
"It is chapter one of the United Nations Charter and it is the basic human right of all people."
Mr Edwards confirmed he would try to hand a formal letter to the Argentine delegation at the meeting, but admitted he did not know if she would receive it.
Mr Edwards and Mr Summers will be accompanied by a delegation of six younger Falkland Islanders.
One of them, Michael Poole, told Sky News Online that the 3,000 people living there had already chosen to be a UK territory, and they were fed up of Argentina's bogus claims.
He said: "We're very happy to be British, very happy to have the support of the British government, and we hope for that to continue in the future."
UN diplomats have described President Fernandez's decision to come to New York as "odd".
The committee she is speaking at has little political influence and tends to issue the same call every year: for all sides to open negotiations about the status of the Falkland Islands.
It is a call the UK will reject, just as it rejects the premise of the meeting in the first place.
Diplomats have also suggested President Fernandez is ratcheting up tension over the Falklands as a way of distracting from her own domestic political problems.
Her government has accused the UK of "militarising" the South Atlantic by sending a destroyer to the region and deploying Prince William on a tour of duty to the Islands .
Four months ago Argentina's foreign minister Hector Timerman called the islands "the last refuge of a declining empire".
UN leader Ban Ki-Moon appealed to both sides to avoid an "escalation" of their sovereignty battle at such a sensitive time.
The UK has accused Argentina of trying to impose an economic blockade on the Falklands by making shipping and flying to and from the islands more difficult, and for declaring UK companies exploring for oil nearby "illegal".
On Tuesday the Falklands government announced it would be holding a referendum on the Islands' political status next year, aiming to bring to an end the dispute over what the people living there want.