HAVANA - A complete islandwide power failure struck Cuba on Friday for the second time this week as the country of nearly 10 million continues facing an unreliable electricity network and fuel shortages tied to a U.S. energy embargo.

While full blackouts have grown more frequent across the Caribbean nation, consecutive national events days apart remain uncommon. Cuba's Electric Union verified the outage on X.

Officials stated the blackout resulted from a fluctuation in parameters after a failure on a line linking the provinces of Santa Clara and Sancti Spiritus.

The nation's electrical system remains especially vulnerable owing to neglected aging infrastructure, with some plants over 30 years old, along with scarce fuel supplies.

Prime Minister Manuel Marrero wrote on social media that it has been another very difficult week under the energy blockade impact, with two disconnections of the National Electric System, almost no fuel for plants, and several units offline.

Authorities noted that power restoration to some areas has already started.

On Monday another major blackout affected nearly the entire population. Officials said service recovery from that event advanced gradually during the week.

Friday's total grid collapse marks the fourth such event this year. A mid-May outage hit eastern provinces while a mid-March failure covered the whole island.

Fuel shortages have persisted since January after U.S. President Donald Trump threatened tariffs on countries selling oil to Cuba, worsening the ongoing economic crisis. Public transport has mostly stopped and officials canceled tens of thousands of surgeries.

Cuba produces only 40 percent of needed fuel. The 730,000 barrels from a Russian tanker in late March ran out by April's end. The government continues rationing power through planned outages that can last more than 24 hours straight.