CARACAS, Venezuela — A day before the United Nations General Assembly voted overwhelmingly to condemn President Bashar al-Assad of Syria this month for his bloody crackdown on the uprising in his country, President Hugo Chávez of Venezuela was conducting a very different kind of diplomacy on his own.
A ship owned by the Venezuelan state oil company sailed into the Syrian port of Baniyas, its location captured by a satellite system that tracks ship movements. The ship, making its second trip to Baniyas since December, appeared to be carrying fuel to help prop up the embattled Mr. Assad.
The Venezuelan shipment flies in the face of international efforts to isolate Mr. Assad and pressure him to step down, but Mr. Chávez is no stranger to such controversy. Last month, he played host to another Middle Eastern ally, President Mahmoud Ahmadinejad of Iran, ridiculing Western claims that Iran was seeking to be able to produce nuclear weapons.
Still, Mr. Chávez is at the start of what could prove to be a difficult re-election campaign overshadowed by his battle with cancer, and the political equation here may be shifting. While provocative moves like oil shipments to Syria play well among Mr. Chávez’s staunchest backers, they may prove to be a liability among voters who resent his oil tanker diplomacy.
The Venezuelan ship, the Negra Hipólita, arrived in the Syrian port on Feb. 15, according to John H. Paskin, the chief executive of Commodity Flow, a company based in London that compiles satellite data and other information to track the movement of ships.
He said the ship left a Venezuelan refinery complex at Puerto La Cruz on Jan. 25. The Puerto La Cruz complex produces gasoline, diesel, jet fuel and fuel components, according to the Web site of the state oil company, Petróleos de Venezuela, known as P.D.V.S.A.
Mr. Paskin said the tracking data showed that the ship made a previous trip to Syria last fall, leaving a Venezuelan refinery complex on the Paraguaná Peninsula on Oct. 15 and arriving at Baniyas on Dec. 1.
The ship is named after a slave who was a wet nurse and nanny to Simón Bolívar, the national hero, whom Mr. Chávez idolizes. A Venezuelan shipping broker said the shipment, first reported by Reuters, probably carried diesel and possibly other types of fuel.
Asked about the shipments and whether the fuel delivered could be used by Syria’s military, Mr. Chávez answered by referring to his country’s oil shipments to the United States, Venezuela’s largest customer.
“Have we by any chance asked the United States what it does with the fuel we sell to the United States?” he said in an exchange with reporters at the presidential palace last week. “Have we by any chance allowed anyone to impose conditions on our sale of petroleum to the United States?” He said that the answer was no and added, “We are a free country.”
William A. Ostick, a State Department spokesman, said that American or European sanctions did not prohibit shipments of fuel to Syria.
“We continue to work with the friends of the Syrian people to increase pressure on the Assad regime to get him to step down,” Mr. Ostick said.
Venezuela has some of the world’s largest oil reserves, and Mr. Chávez has benefited from the high price of oil as he uses petroleum revenues to finance social programs at home. He has also used oil aggressively to promote his interests abroad.
He has helped prop up the debilitated Cuban economy through shipments of oil in exchange for doctors to staff Venezuelan clinics and for other aid.
China has become a major buyer of Venezuelan oil, and loans and investments have followed.
Venezuela has backed isolated Middle Eastern governments before, sending a gasoline blending component to Iran in late 2010 and early 2011, action that drew a rebuke from the United States.
In supporting autocratic governments in the Middle East, Mr. Chávez has portrayed them as the victims of imperialist aggression. He sounds the same message at home, and it is carried daily on state media: Mr. Chávez as a champion standing up to the bullying of the United States.
Such views resonate with Mr. Chávez’s followers.
“The United States wants to impose a new hegemony,” said Pedro Correa, 56, an industrial draftsman from Santa Teresa del Tuy, a city about an hour’s drive south of central Caracas, who supports Mr. Chávez.
But many Venezuelans who oppose Mr. Chávez are quick to voice resentment of his petro-diplomacy, especially the generous deal with Cuba.
“He gave our riches away to other countries,” said Carlos Cedeño, 55, a driver for a concrete company in Maracay. He supports Mr. Chávez’s opponent in the presidential election this year, Henrique Capriles Radonski.