( CNN ) Cuba has freed all 53 political prisoners it had promised to release as part as an historic rapprochement with the United States , a U.S. official said Monday . The names of the prisoners were not given . The move comes as part of a deal announced December 17 to normalize relations between the United States and Cuba . Both nations have previously released political prisoners in a show of goodwill . American Alan Gross headed home on `` humanitarian '' grounds from Cuba last month . In a separate swap , a U.S. intelligence source held for 20 years was released in exchange for three jailed Cuban spies . U.S. State Department spokeswoman Marie Harf provided details about the timing of the releases on Monday . A small number of the 53 prisoners identified by the U.S. side were released in the summer and fall , she said . A few additional prisoners were released before December 17 . `` In the period since then ... the Cuban government has released all 53 persons whose names were shared by the U.S. government , '' Harf told reporters . She added : `` We know there are going to be human rights concerns we still have when it comes to Cuba , but we are very pleased that they followed through on this commitment . '' Her point was echoed by Erika Guevara Rosas , Americas director at Amnesty International , who commented on the releases last week . `` Prisoner releases will be no more than a smokescreen if they are not accompanied by expanded space for the free and peaceful expression of all opinions and other freedoms in Cuba , '' she said . According to Amnesty , which cited the Cuban Commission for Human Rights and National Reconciliation , 8,899 short-term detentions were reported last year , compared with 6,424 in 2013 . `` The good will expressed by the Cuban authorities with this series of releases must absolutely translate into the implementation of a new human rights agenda . Respect for freedom of expression , assembly and association must be the next step if the Cuban authorities want to keep their credibility in the face of a world which is watching them , '' the Americas director said .
The move comes as part of a plan to normalize relations between the United States and Cuba . The rest of the prisoners were not released .