Mercosur is key to Venezuela's development, Mr Chavez says

The summit, in Cordoba, Argentina, is expected to be enlivened by the presence of fiery Venezuelan president Hugo Chavez.

There are also rumours that Cuban leader Fidel Castro will be making an appearance after a three-year absence.

The event is primarily about forging links in Latin America, where countries have so often been divided.

Insults

Among the issues are a high-profile dispute between Argentina and Uruguay over proposals to build a paper mill near the border of the two countries which has been heard at the International Court of Justice at The Hague.

MERCOSUR Argentina Brazil Paraguay Uruguay Venezuela Associate members Ecuador Chile Bolivia Peru Colombia Profile of Mercosur

Earlier this month, the court backed Uruguay's plans to build the mill near an Argentine river. Argentina has voiced concerns about the potential environmental costs of the venture.

Bolivia wants to talk to Chile about access to the sea while another lively meeting will involve Mr Chavez and the outgoing Peruvian president, Alejandro Toledo, who have been hurling insults at one another.

A planned trans-continental oil and gas pipeline and the price of Bolivian gas are also on the agenda.

Cordoba was once the home of the Argentine revolutionary, and Fidel Castro's comrade in arms, Ernesto "Che" Guevara.