The US has ramped up its campaign to force political change in communist Cuba by indicting former president Raul Castro on murder charges.

The US charged Castro, aged 94, with one count of conspiracy to kill US citizens, four counts of murder and two counts of destruction of aircraft, court records show.

The charges stem from a 1996 incident in which Cuban jets shot down two civilian planes, killing four people — three of them Americans.

The indictment comes as US President Donald Trump has pushed for regime change in Cuba, where Castro’s communists have been in charge since his late brother Fidel Castro led a revolution in 1959.

The move is a major escalation of a US pressure campaign against the island’s communist government and could be a tipping point.

Five ‌other people are also named as defendants in the case.

Trump said it was a “big moment” for Cuban Americans and people who wanted to go back to Cuba.

“It’s a very important day,” he said on Wednesday (local time). “Cuba is on our minds.”

Acting US Attorney-General Todd Blanche explained the charges at an event to honour the victims.

“My message today is clear: The United States and President Trump does not and will not forget its citizens,” Blanche said to applause in a packed auditorium of government officials and Cuban Americans in Miami.

Castro, 94, last appeared in public in Cuba earlier this month. There is no evidence that he has since left the island or that the government would allow him to be extradited.

Earlier on Wednesday, Trump called Cuba a “rogue state harbouring hostile foreign military”.

“From the shores of Havana ⁠to the banks of the Panama Canal, we will drive out the forces of lawlessness and crime and foreign encroachment,” he said at a Coast Guard Academy event in Connecticut.

Cuban President Miguel Diaz-Canel said on Monday that the island did not represent a threat.

Members of Miami’s large Cuban American community gathered outside the city’s Freedom Tower ahead of the ceremony.

“We all hoped for a long time, for many years that this would happen,” said Bobby Ramirez, a 62-year-old musician who left Cuba in 1971 when he was seven years old.

The ceremony iwas held on the anniversary of the end of a four-year US military occupation of Cuba on May 20, 1902, which itself followed centuries of Spanish ‌colonial rule.

Cuba’s government does not consider ​the date to mark the country’s independence day, arguing that it remained subservient to the US until the 1959 revolution.

In a post on X, Diaz-Canel said that in Cuban history, May 20 signified “intervention, interference, dispossession, frustration”.

Under Trump, the US has effectively imposed a blockade on Cuba by ​threatening sanctions on countries ‌supplying it with fuel, triggering power outages and exacerbating its worst crisis in decades.

US Secretary of State Marco Rubio earlier on Wednesday offered Cuba $US100 million ($140 million) in aid, and blamed its leaders for shortages of electricity, food and fuel.

Cuban Foreign Minister Bruno Rodriguez called ​that offer cynical, citing the “devastating effect” of the economic blockade.

-with AAP