Thee Cuban intelligence agents have been given heroes' welcomes as they landed back in their homeland after 16 years in prison in the US.
It comes as US President Barack Obama announced his country will restore diplomatic relations it severed with Cuba more than 50 years ago.
As part of a prisoner swap under the new policy, Cuba freed American Alan Gross in exchange for the three Cubans held by the United States.
U.S. Senator Marco Rubio said on Wednesday he would "make every effort" to block moves by President Barack Obama toward normalising relations with the Cuban government.
"The president's decision to reward the Castro regime and begin the path toward the normalization of relations with Cuba is inexplicable," Rubio said in a statement.
The Florida Republican senator, who is Cuban-American, said he would use his role as chairman of the Senate Foreign Relations Committee's Western Hemisphere subcommittee in the new Congress to try to block the plan.
The Democratic presidential candidate may also have shown his cards on his choice of running mate.
The US president also shared a post on Twitter accusing Dr Anthony Fauci of misleading the public over hydroxychloroquine.
Fears over an impending second wave of coronavirus dominates Wednesday’s front pages.