Cuba’s President Miguel Díaz-Canel on Wednesday lashed out at the “almost daily” threats from the U.S. and pledged to meet the Trump administration’s move to choke off the island’s fuel supplies with “unyielding resistance.”

His comments come after the communist-run island nation of roughly 10 million people partially reconnected its power grid on Tuesday evening, energy officials said, following a nationwide blackout that reportedly lasted for more than 29 hours.

Cuba’s gird operator, UNE, said on social media that it was gradually restoring electricity to all provinces and cities around the country, without providing further details on the cause of the power grid’s collapse.

The country, which is located just 90 miles from Florida, is currently facing its biggest test since the fall of the Soviet Union.

The U.S. has imposed an oil blockade on the island since January, shortly after its ally and a key provider of oil, Venezuelan President Nicolás Maduro, was seized in an audacious military operation.