The Cuban government has said 32 of its nationals were killed during the US operation to capture Venezuelan leader Nicolás Maduro.
It said the dead were members of its armed forces and intelligence agencies, with two days of national mourning declared.
A short statement did not elaborate on the role of the Cubans in Venezuela, but the two governments are long-standing allies, with Cuba providing security support in exchange for oil.
Cuban President Miguel Diaz-Canel said they had been providing protection to Maduro and his wife at the request of Venezuela.
An official government statement read: Our compatriots fulfilled their duty with dignity and heroism and fell, after fierce resistance, in direct combat against the attackers or as a result of bombings on the facilities.
Venezuela has not confirmed how many people were killed during the US raid on Maduro's compound in Caracas on Saturday. The New York Times, citing an unnamed Venezuelan official, reported that the death toll stood at 80 and was expected to rise.
In the days following the capture of Maduro, questions have been raised over whether the Trump administration could consider a similar operation against Cuba. Speaking to reporters, US President Donald Trump suggested military action would not be necessary because Cuba is ready to fall. He stated: I don't think we need any action. Looks like it's going down. It's going down for the count.
On Saturday, US Secretary of State Marco Rubio described Cuba as a disaster run by incompetent, senile men.
In July last year, Trump signed a memorandum imposing tighter restrictions on Cuba, reversing earlier easing of pressure by his predecessor, Joe Biden, stating that it would end economic practices that disproportionately benefit the Cuban government, military, intelligence, or security agencies at the expense of the Cuban people.
The blockade initially imposed in 1962 has been a longstanding element of U.S. foreign policy towards Cuba, continuing despite international calls for its cessation.
