The US has removed sanctions from four Greek-linked tankers blacklisted amid a push to cripple Venezuela's oil trade.

The 300,000-dwt Voyager I (built 2003), 306,500-dwt Seahero (built 2006), 106,361-dwt Euroforce (built 2002) and 105,850-dwt Delos Voyager (built 2003), along with their registered owners, were dropped from the US sanctions regime on Thursday.

Thenamaris, the Seahero's manager, said in a statement that the company "has always placed the highest priority on regulatory compliance" including sanctions.

"In addition to adopting a firm policy prohibiting any carriage of crude oil from Venezuela for the vessels under its management for as long as US sanctions against Venezuela remain in place, Thenamaris has further enhanced its compliance controls, including its sanctions protocol and associated internal processes," the statement read.

NGM Energy, which manages the Voyager I, made a similar statement.

"They have worked closely with US authorities to promptly resolve this matter," the company said of itself and Sanibel Shiptrade, the Voyager I's registered owner.

"In the wake of this event, NGM Energy has implemented enhanced compliance controls and increased coordination with all relevant authorities to head off future sanctions risk."

The Seahero, owner Adamant Maritime, the Voyager I and its owner were sanctioned on 2 June, along with two other tankers, in what was interpreted as a "warning shot" for Greek owners still willing to do business with the South American country.

The Delos Voyager Shipping-owned Delos Voyager and the Romina Maritime-owned Euroforce were added two weeks later for shipments of Venezuelan crude to the South China Sea and Malaysia earlier this year.

The US placed sanctions on Venezuela's state-run oil company PDVSA in early 2019, in the hope of toppling the Nicolas Maduro regime and elevating opposition leader Juan Guaido to the presidency.

The move pushed Venezuela into doing more business with Russia, China and Iran, with the latter delivering 1.55m gallons of gasoline to the country in May and June.

At the same time, the US was threatening sanctions against 40 or more tankers.

The US has insisted that its sanctions against companies doing business with Venezuela are intended to "bring about a positive change of behaviour" from shipowners and managers.

Geoffrey Pyatt, the US ambassador to Greece, reportedly told the Union of Greek Shipowners in mid-June that sanctions would be reversed so long as commercial activity with Venezuela was avoided.