While many world leaders have condemned Syrian President Bashar al-Assad, the embattled leader has found an ally in Venezuelan President Hugo Chavez.
The South American country's state-run oil company has sent large diesel shipments to Syria, despite international sanctions.
In recent months, Venezuela supplied Syria with at least three shipments of diesel fuel in exchange for Syrian naphtha, a refined petroleum product, according to a May report from the U.S. Congressional Research Service.
In late May, Syria's oil minister said that an oil tanker loaded with 35,000 tons of diesel fuel had arrived in his country from Venezuela, the state-run Syrian Arab News Agency reported. At the time, he said Venezuela was preparing another tanker to head to Syria.
Citing Venezuelan and Syrian government documents, the Wall Street Journal reported this week that a fourth shipment was in the works. CNN has not independently confirmed that report.
Chavez and the president of Venezuela's state-run oil company have defended their sovereign right to send fuel to Syria.
"If they need diesel, and we can provide it, there is no reason not to do it," Rafael Ramirez, Venezuela's energy minister, told reporters in February, according to state media reports.
Ramirez, who also heads the state-run oil company, said Venezuela was not worried about possibly facing international sanctions for sending fuel to the Middle Eastern nation.
"We cannot determine our foreign policy with fear of U.S. sanctions," he said. "We have said that those truly don't matter to us."
Chavez and al-Assad have a "longstanding personal fraternity," Venezuela's foreign ministry said in a statement after the two leaders spoke on the phone in April.