Cuba's national electric system suffered yet another total collapse on July 6, the state-run Cuban Electric Union (UNE) said, the latest in a string of islandwide blackouts to hit the country since late 2024 as a US blockade on oil shipments squeezes the island's power supply.

The UNE said on its official channel that the cause of the disconnection was still unknown and under investigation, adding that further details would be released once available.

The utility said it was applying protocols for a gradual recovery of the grid, prioritising the creation of local microsystems to restore power to hospitals, aqueducts and other essential services.

The outage comes amid tightening US economic pressure on Havana. US President Donald Trump signed an executive order in January threatening tariffs on countries that export or facilitate fuel shipments to Cuba.

Pressure on the communist-run island intensified after US forces captured Venezuelan president Nicolás Maduro, a close ally of Havana, in a military operation in early January, severing a supply of Venezuelan oil that had propped up Cuba's economy for years. Trump told reporters shortly afterwards that Cuba "looks like it is ready to fall" and has since suggested the US could carry out a “friendly takeover” of the island, without elaborating.

The de facto oil blockade has placed additional strain on a generation network that already depends on ageing Soviet-era thermal plants and has been pushed beyond the breaking point by the US fuel embargo. Cuba's thermal blocks include ten units from the former Soviet Union alongside Japanese, Czechoslovak and French-built generators, most of which have been in operation for more than 30 years, with seven blocks running for over four decades.

Cuba has received only one oil shipment from Russia since the blockade tightened this year. A Russian-flagged tanker, the Anatoly Kolodkin, delivered 730,000 barrels of crude to the Bay of Matanzas on March 30, the first vessel to reach the island in three months, after Washington allowed the delivery on humanitarian grounds. Those supplies had reportedly been exhausted by late April. A second Russian tanker, the Universal, carrying nearly 270,000 barrels of diesel, stalled roughly 1,600 km off the Cuban coast after departing Russia in April and later turned around off the coast of Brazil in late May without reaching the island.

Havana has attributed the repeated grid collapses, which have strained the country's healthcare infrastructure and dealt a final blow to the once-thriving tourism industry, to the cumulative effects of the decades-old US trade embargo, which it says restricts its access to the fuel, spare parts and financing needed to maintain and modernise its power sector.