The US on Wednesday announced criminal charges against Cuban leader Raul Castro, brother of revolutionary figure Fidel, accusing him of ordering planes carrying Cuban exiles to be shot down in 1996.
Hours earlier, US Secretary of State Marco Rubio released an impassioned, Spanish-language video aimed at Cubans in which he blamed Havana for their current suffering.
Mr Castro, the 94-year-old Deputy of the National Assembly of the People's Power of Cuba, and five others were charged with murder as well as conspiracy to kill US nationals, acting Attorney General Todd Blanche said to resounding applause during a ceremony honouring victims of the incident.
"Nations and their leaders cannot be permitted to target Americans, kill them, and not face accountability," Mr Blanche said.
Four people were killed when two civilian aircraft operated by Brothers to the Rescue were shot down over international waters by military aircraft from Cuba in 1996, he added.
The murder and conspiracy to kill US citizens charges carry sentences of up to life imprisonment or the death penalty, while the other charges carry up to five years in prison.
The announcement comes on the date marking the establishment of the Cuban republic – and the end of the US occupation – in 1902.
US President Donald Trump has targeted Cuba with increasingly bellicose rhetoric since returning to office, calling it a failed state and threatening the communist-run island. The US has also established an oil blockade around the country in recent months, compounding a punishing embargo Washington put in place in the 1960s.
“America will not tolerate a rogue state harbouring hostile foreign military, intelligence and terror operations just 90 miles from the American homeland,” Mr Trump said.
It comes after a report, quoting US officials, that Cuba had acquired 300 drones from Russia and Iran, with which they planned to attack the US base at Guantanamo Bay.
Cuban President Miguel Diaz-Canel has said, however, that the island does not represent a threat to the US. He said that were the US to take action against Cuba, it would "trigger a bloodbath with incalculable consequences".
Critics have said the drones and the charges against Mr Castro are an attempt to justify an impending US invasion. In January, US special forces carried out a raid in Caracas, Venezuela that led to the capture of president Nicolas Maduro, who was brought to a New York court to stand trial on drugs and weapons-related charges.
Mr Blanche said the indictment was not a "show indictment".
"There was a warrant issued for his arrest, so we expect that he will show up here by his own will or by another way," he said.
Mr Rubio, in the video posted on X, offered Cubans a “new relationship” with the US, saying Washington could provide $100 million in aid for the people, distributed through non-government channels. Mr Rubio placed the blame for current fuel and food shortages, as well as power cuts, on the Cuban leadership.
“The reason you are forced to survive 22 hours a day without electricity is not due to the oil blockade by the US,” he said. “The real reason you don't have electricity, food or fuel is because those who control your country have plundered billions of dollars but nothing has been used to help the people.”
Cuban Foreign Minister Bruno Rodriguez said Mr Rubio was repeating a “mendacious script” and acting as the “mouthpiece of corrupt and vengeful interests, concentrated in South Florida and which do not represent the feelings of the majority of the American people, nor of the Cubans who live there”.
