During the tour, Chavez called for the strengthening of cooperation among South American countries to achieve energy integration in the region.

In Buenos Aires, the first stop of his four-nation tour that started Monday, Chavez signed a five-year deal on energy cooperation with his Argentine counterpart Nestor Kirchner and pledged to ensure energy supplies to Argentina.

Under the agreement, Venezuela will build a facility in Argentina to reprocess liquefied natural gas shipped from Venezuela to supply customers in Argentina.

The deal also created Petrosuramerica, a joint-venture between the two nations' state-run oil companies that will mainly deal with crude oil, natural gas, refining and petrochemicals.

During his trip to Uruguay, Chavez agreed to supply the country with oil and gas at discounted prices. Uruguay will invest in developing oil fields in Venezuela and increase oil trading.

A deal between the two nations also envisions cooperation in expanding Uruguay's only oil refinery.