The US has charged former Cuban leader Raúl Castro with conspiracy to kill US nationals and other crimes over the 1996 downing of two planes between Cuba and Florida.
The case unveiled on Wednesday accuses Castro and five others in the shooting down of the aircraft belonging to Cuban-American group Brothers to the Rescue and killing four people, including three Americans.
Castro, now 94, was then head of the country's armed forces and faced international condemnation over the crash.
As the US seeks to exert increasing pressure on Cuba's communist rule, President Miguel Díaz-Canel called the charges "a political manoeuvre, devoid of any legal foundation".
Speaking at Freedom Tower in Miami, Acting Attorney General Todd Blanche announced that the US would also charge Castro with destruction of aircraft, and four individual counts of murder over the deaths of Armando Alejandre Jr, Carlos Alberto Costa, Mario Manuel de la Peña, and Pablo Morales.
"The United States, and President Trump, does not, and will not, forget its citizens," Blanche said.
The charges must be argued in a US court, with some carrying the possibility life terms. The murder charges each carry a maximum penalty of death or life imprisonment.
The justice department's new charges take aim at a key figurehead of Cuba's communist leadership when it is facing intense US pressure to make significant political and economic reforms to its one-party rule there.
"I think the strategy is to increase the pressure gradually to the point where the Cuban government will give in and surrender at the bargaining table," said Wiliam LeoGrand, a expert on Latin American politics at American University.
The US has issued sanctions on the country and imposed a blockade on oil to Cuba that has resulted in blackouts and food shortages.
Earlier on Wednesday, US Secretary of State Marco Rubio issued a message to the Cuban people timed to the country's independence day.
"President Trump is offering a new path between the US and a new Cuba," Rubio said.
Rubio told citizens of the island that a Cuban military run conglomerate known as GAESA is primarily responsible for the blackouts and food shortages that the country continues to endure.
GAESA owns or operates most of the lucrative parts of the Cuban economy from the ports to the petrol pumps to five-star hotels.
In response to Rubio's message, Díaz-Canel accused the US of lying and imposing a collective punishment on the Cuban people.
Díaz-Canel also said that the indictment of Castro was being used to "justify the folly of a military aggression against Cuba" and accused the US of distorting the facts around the downing of the plane.
He claimed that Cuba acted in "legitimate self-defence within its jurisdictional waters".
Asked by reporters about the prospects of bringing Castro to the US to face charges, Blanche responded that there was a warrant for his arrest.
He did not confirm whether the US would try to capture Castro, but said, "we expect he will show up here, by his own will or another way".
American University's LeoGrande said he believes the US is ready to capture the former Cuban leader "if the Cubans don't surrender at the bargaining table".
In January, the US staged a military operation to seize former Venezuelan President Nicolás Maduro and bring him to the US, after the justice department indicted him.
It transformed Venezuela's relationship with Washington, something LeoGrande cautioned would be unlikely to have the same effect in Cuba, noting Castro retired almost a decade ago.
Nearly 95 years old, Castro, the brother of late Cuban leader Fidel Castro, remains an influential figure, acknowledged on the island as the surviving "leader of the Cuban Revolution".
He has relinquished his active government and party roles, but during his 2008-2018 presidency, he and former US president Barack Obama presided over a short-lived thaw in Washington-Havana relations.
Blanche said he would "not compare cases" between Castro's and that of Maduro.
President Donald Trump was asked about the political aspect of Wednesday's indictment.
"A lot of those people are related to me in the sense that I've had such a great relationship with Cuban-Americans," Trump said. "On a humanitarian basis, we're here to help."
The Miami centre where US officials announced the indictment of Raúl Castro was full of Cuban Americans, mostly representing Cuban exile organisations that have for decades led opposition of the Cuban government from within the United States.
Surrounded by pictures of the four people who died in the 1996 crashes, many at the Miami event described being thrilled by the news.
"It was time, 67 years of that murderous regime," said Isela Fiterre. "Raúl Castro did not merely kill four individuals. Over the course of many years, he has killed countless people," Fiterre said.
She said it is never too late for justice and that she is grateful to the Trump administration for taking this step.
Another attendee, Mercedes Puid-Soto, echoed those sentiments.
"I feel very happy. Justice has been served," she said. "It's very important that the families can close that chapter, and we Cubans too."
Still looming over Blanche's announcement was the answer to "whether the Trump administration will use this indictment in a similar way that it used the indictment against Maduro, as a justification to carry out a military operation under the cover of a law enforcement action," said Roxanna Vigil, an international affairs fellow at the Council on Foreign Relations.
"It's unlikely that the Cuban regime will surrender to the United States without a fight," Vigil noted. "And any move that includes working with the Cuban regime would be very difficult for the Cuban diaspora in the United States to accept."
US and Cuban representatives, including Raúl Castro's grandson Raúl Guillermo Rodriguez Castro, have held "conversations" in recent months, but US charges against the former president are unlikely to smooth these contacts.
On the contrary, the Cuban side showed signs of further entrenching into its "no surrender, no concessions" position against US pressure, with Cuban state media outlets blasting what they called the "false accusations".
