President Hugo Chavez said Saturday that he is expanding his Venezuela's Petrocaribe oil-supply pact to include Guatemala. Through the pact, oil-rich Venezuela provides nations with oil under preferential terms, including long-term loans and the option of paying for at least some of the costs with goods and services. “It is an obligation to help the weakest” countries, Chavez said in a televised address. “The United States would pay us $200 a barrel for oil – give it to me then,” said Chavez, whose nation is the world's 10th largest oil producer. “Now Haiti, no. Haiti gets preferential treatment. Socialism says: To everyone according to their needs.” Chavez said nearly 20 heads of state are attending a Petrocaribe summit in the Venezuelan city of Maracaibo this weekend, where Guatemalan President Alvaro Colom will formalize his country's membership. Venezuelan Oil Minister Rafael Ramirez said the pact “strengthens nations in the region facing a difficult market.” He was referring to oil prices that have topped $140 a barrel. Oil economist Mazhar Al-Shereidah believes soaring prices have motivated countries including Guatemala to join. But the agreement is an economic “sacrifice” for Venezuela, he said. Al-Shereidah added that while Chavez's critics say he is using the pact to expand his political influence in the region, such an effect may be minimal. Referring to Chavez's 2006 bid to gain Venezuela a seat on the UN Security Council, Al-Shereidah said: “None of his friends supported him.”