Venezuelan President Hugo Chavez presided Friday at the opening of a regional petroleum summit in Cuba, pressing his efforts to counter U.S. influence in Latin America and the Caribbean by offering cheap oil.

Chavez, who wants to use Venezuela's vast oil reserves to help create a "confederation of republics" free of U.S. interests, called on regional leaders to ban together against the failed "dictatorship of world capitalism."

Opening the Petrocaribe summit in Cienfuegos, a southern coastal city about 155 miles from Havana, Chavez said his plan should go beyond mere financing mechanisms and suggested that some countries repay the oil with social services.

Chavez on Thursday suggested the summit could pave the way for other countries to repay the oil under plans modeled on Venezuelan agreements with Cuba. Cuba repays by providing doctors and other health professials who offer free services in impoverished areas of Venezuela.

He also called for creating an international fund to promote alternative energy sources.

"Despite the Yankees, our gas is at the service of Venezuela first, and next to our brothers in the Caribbean," Chavez said in a reference to the United States.

Venezuela has the largest oil reserves outside the Middle East and is the fourth-largest supplier of crude to the United States.

Chavez spoke as leaders studied the Petrocaribe pact under which his country provides fuel to countries around the region through long-term, low-interest financing.

Chavez blasted Washington's proposals for free trade pacts.

"Free trade doesn't exist," he said. "What exists ... is a dictatorship of world capitalism." He said Petrocaribe is based on fairness and promoting social equality — not profit margins.

Venezuela's president also paid tribute to his friend and ally, the ailing Fidel Castro, who before failing ill had been the central figure at such regional events.

The 81-year-old Castro has not been seen in public since ceding power to his younger brother Raul following emergency intestinal surgery 17 months ago. But Chavez met behind closed doors with him for "an emotional" 2 1/2 hours Thursday, official media said.

Although both Chavez and Raul Castro gave Friday's opening remarks, it was the more talkative Venezuelan who was center of attention during the daylong summit of Petrocaribe, which was created in 2005 as an alternative to Washington's unsuccessful Free Trade Area for the Americas and encompasses 16 Latin American and Caribbean nations.

Raul Castro said that in the face of soaring international energy costs, the pact ensures Petrocaribe members are in a "privileged position."

Venezuela provides about $5 billion to countries in the region, according to Chavez, who promotes Petrocaribe as part of a larger effort to create a regional confederation from Argentina to Cuba that will help counter U.S. influence.

Later Friday, Chavez was to reopen an oil refinery that his country helped Cuba renovate after it was left idle following the collapse of the Soviet Union, the latest evidence of how Venezuela has replaced the support Cuba enjoyed from Moscow.

With Venezuela's assistance, more than $136 million in improvements have been made to the refinery, which will employ 1,200 people when fully operational.

The refinery is expected to process 65,000 barrels of crude daily and then increase capacity, eventually pushing Cuba's overall daily production to more than 100,000 barrels a day.

Venezuela also sends nearly 100,000 barrels of subsidized oil a day to Cuba. In exchange, it gets social services, including thousands of Cuban doctors who treat poor patients in the South American nation. Fidel Castro recently wrote that overall annual trade with Venezuela has reached $7 billion.

Presidents Daniel Ortega of Nicaragua, Rene Preval of Haiti and Leonel Fernandez of the Dominican Republic were attending the summit as well as the leaders of Antigua and Barbuda, Belize, Dominca, Guyana, St. Kitts and Nevis, St. Vincent and the Grenadines, and Jamaica.