Cuba's national power grid suffered a "total disconnection" on Friday, operator UNE said on US social media platform X.

"Total collapse of the National Electric System," UNE said at 4.30 pm local time (2030GMT), without providing the cause of the outage.

This is the second nationwide blackout in less than a week, after one on July 6.

Cuba grapples with its worst economic crisis in decades, including severe fuel shortages and repeated power failures.

Official media reported that the economy contracted sharply in the first half of 2026, while average daily power outages have reached 20 hours, and the electricity deficit climbed to 1,955 megawatts.

Authorities have blamed much of the deterioration on tighter US measures, saying Washington has disrupted oil supplies, pressured companies doing business with Cuba, and restricted the island's access to international credit and financing.

The White House said May 1 that President Donald Trump signed an executive order imposing new sanctions on Cuban officials and entities, citing repression and threats to US national security and foreign policy.

In January, Trump signed an executive order declaring a national emergency and establishing a mechanism to impose tariffs on goods from countries that sell or supply oil to Cuba, according to the White House. (AA)