The Cuban government has released some of the 53 political prisoners on a US list, the state department has said.
Spokeswoman Jen Psaki said Washington hoped to see all those on the list released soon but did not specify who was now free.
Signalling a historic shift, last month US President Barack Obama ordered his administration to start re-establishing normal relations with Cuba.
This month Cuban and US officials will meet in Havana.
“They have already released some prisoners… Obviously we would like to see this completed in the near future,” Ms Psaki said.
“This list is not to be seen as the end of our discussion on human rights with the government of Cuba.”
Critics of President Obama have raised concerns about human rights abuses in Cuba.
Senator Marco Rubio, a leading critic of the president on the Cuba question, called for the postponement of this month’s talks until political prisoners in Cuba are released.
Senator Rubio and other Cuban-Americans members of Congress have argued that Mr Obama’s change of policy could provide legitimacy and money for Havana while it still continues to violate human rights.
He said he and others would seek to slow or block moves towards normalising ties with Cuba.
The Congress is expected to hold hearings on President Obama’s Cuba policy in the first weeks of the new Congress, which was sworn in on Tuesday.