HAVANA (AFP) — Cuba’s leader on Tuesday said the United States would face “unbreakable resistance” if it tries to take over the impoverished island nation, as communist authorities scrambled to fix a nationwide electricity blackout.

Cuba’s government is under increasingly crushing pressure, with Washington enforcing an oil blockade and openly stating it wants to end the nearly seven-decade-old US standoff with the one-party communist state.

US Secretary of State Marco Rubio said Cuba’s decision announced this week to let exiles invest and own businesses did not go far enough to allow free-market reforms that the Trump administration demands.

“What they announced yesterday is not dramatic enough. It’s not going to fix it. So they’ve got some big decisions to make,” Rubio, a Cuban-American and vociferous critic of the country’s ruling party, told reporters at the White House.

President Donald Trump, who has heaped pressure on Cuba’s communist government, said Monday he would “take” Cuba, adding: “We’ll be doing something with Cuba very soon.”

But his Cuban counterpart Miguel Diaz-Canel was defiant in the face of Washington’s threats.

“Faced with the worst-case scenario, Cuba has one guarantee: any external aggressor will encounter an unbreakable resistance,” he wrote in a statement on X.

Cuba is open to broad talks with Washington and allowing more investment, but it will not discuss changing its political system, an envoy told Agence France-Presse on Tuesday.

Tanieris Dieguez, Cuba’s deputy chief of mission in Washington, said the two neighboring countries “have a lot of things to put on the table” but that neither should ask the other to change its government.

“Nothing related with our political system, nothing with our political model — our constitutional model — is part of the negotiations, and never will it be part of that,” she said.

“The only thing that Cuba asks for any conversation is respect to our sovereignty and to our right to self-determination.”

The New York Times, quoting unnamed US officials, said the Trump administration has called for Cuba to sack Diaz-Canel, who is seen as resistant to change.

Rubio denied the report late Tuesday, writing on X that the article was “fake” and was among media reports that relied on “charlatans and liars claiming to be in the know” as sources.