By Iain Bruce
BBC News, Caracas
Brazil's president opens talks with his Venezuelan counterpart in Caracas shortly with the aim of cementing what both sides call a strategic alliance.
The Brazilian leader flew into Venezuela on Sunday evening
Luiz Inacio Lula da Silva and Hugo Chavez are expected to sign joint oil and energy projects and discuss the sale of Brazilian fighter aircraft.
Washington expressed concern last week at President Chavez's plans to buy guns and helicopters from Russia.
Mr Chavez is trying to enlist Brazil's support for a South American oil giant.
This would bring together state oil companies from across the continent.
Monday's agreements will not go as far as that.
However, the indication that the two leaders will sign deals for Venezuela's PDVSA to help build and run a refinery in Brazil, and for Brazil's Petrobras to drill for oil in Venezuela, suggests that the Brazilians have moved in President Chavez's direction.
Venezuela's interest in buying Tucano fighter planes from Brazil will also be on the agenda.
In his weekly television show on Sunday, Mr Chavez said the United States had repeatedly delayed the delivery of spare parts for Venezuela's existing F-16 fighters, so he was going to have to look elsewhere.
He dismissed the fears expressed by Washington last week over Venezuela's plans to buy Russian rifles and helicopters as ridiculous.
The two left-wing Latin American leaders have not always seen eye to eye on regional issues.
But both Venezuela and Brazil have referred to this meeting as an opportunity to turn into concrete reality what they call their strategic alliance.