Ireland's Foreign Minister will tell world leaders there is an urgent need for an appropriate deal with the European Central Bank on the country's debt.
He will say: "Failure to conclude negotiations on the promissory note would have a potentially catastrophic effect on Ireland".
Mr Gilmore claimed there was a need for solidarity and certainty in Europe.
German Chancellor Angela Merkel, EU Commission President Jose Manuel Barroso and President of the European Council Herman van Rompuy are among those attending the conference in the Chilean capital, Santiago.
Mr Gilmore will also hold bilateral meetings with the Prime Ministers of France and Australia later.
On Saturday, he discussed a fair resolution of Ireland's bank debt in talks with the Finnish Prime Minister, Jyrki Katainen.
The Tanaiste has also spoken of improving trade links with Chile and Colombia.
The purpose of the summit is to promote better economic cooperation and trade.
It comes after Irish President Michael D Higgins' visited to Brazil, Argentina and Chile in October last year.