Some of the flotilla of about 10 Iranian vessels will also help export Venezuelan crude after discharging fuel, according to people with knowledge of the matter, asking not to be named because the transaction is not public, Bloomberg reported.
The last Iranian fuel shipments sent in early October on three vessels are running out, threatening steeper nationwide shortages with hours-long queues at gas stations.
The current fleet under sail is about double the size of the one that first startled international observers in May, crossing a Caribbean Sea patrolled by the US Navy, to be greeted by Maduro himself upon arrival.
The US has imposed sanctions on state oil company Petroleos de Venezuela (PDVSA) as part of its push to oust President Nicolas Maduro, creating a gasoline shortage in the OPEC nation.