Donald Trump has signalled a new flexibility in allowing oil into Cuba, hours before a Russian oil tanker under US sanctions arrived in the Caribbean island amid a de facto oil blockade imposed by Washington.

Speaking to reporters aboard Air Force One the president said: “If a country wants to send some oil into Cuba, right now, I have no problem whether it’s Russia or not.”

Until now, Trump’s administration had in effect prevented all oil shipments to Cuba in an attempt to pressure the government in Havana, while also issuing a series of threatening statements.

His comments came after the New York Times reported the US would allow a Russian tanker full of crude oil to reach Cuba, granting a lifeline to the island nation amid a worsening energy crisis.

The report said it was unclear why the Trump administration was allowing the shipment to go through. A move by Washington to block the tanker by force, however, could have raised tensions at sea with Russia.

The Russian tanker Anatoly Kolodkin, carrying a humanitarian shipment of 100,000 tonnes of crude oil, has arrived in Cuba, the Interfax news agency reported on Monday, citing the Russian ministry of transport. It said the ship was expected to offload the cargo at the port of Matanzas.

The thousands of barrels of crude would provide significant relief to Cuba, which, according to the president, Miguel Díaz-Canel, has not received any oil imports for three months, leading to strict rationing of gasoline and exacerbating an energy crisis that has resulted in multiple power outages across the Caribbean island nation.

Cuba lost its main regional ally and oil supplier in January when US forces captured Venezuela’s president, Nicolás Maduro. Trump subsequently threatened to impose tariffs on any country sending oil to Cuba and has mused about “taking” the island.

Jorge Piñon, an expert on Cuba’s energy sector at the University of Texas at Austin, said he was surprised the US did not try to intercept the Russian tanker before it approached Cuba. Once the boat entered Cuban waters, he said, it “is almost impossible for the US government to stop it”.

The US oil blockade has forced Cuba to impose emergency measures to conserve fuel, including strict rationing of gasoline. Fuel prices have soared, public transport has dwindled and some airlines have suspended flights to Cuba, hitting the country’s fragile economy.

The Russian shipment could be converted into 250,000 barrels of diesel, enough to cover the country’s demand for about 12 and a half days, according to Piñon.

With Reuters and Agence France-Presse