Cuba has signed two legally binding human rights agreements at the UN in New York, just days after Raul Castro was sworn in as the new president.
The covenants - part of the Universal Declaration of Human Rights - commit Cuba to freedom of expression and association, and the right to travel.
Correspondents detect a possible signal of a shift in human rights policy.
Critics of the Castro government have called on it to make good on the agreements by freeing dissidents.
Cuban Foreign Minister Felipe Perez Roque, who signed the agreements, rejected suggestions of any link to the recent change in power, insisting they merely "formalised" rights enjoyed by Cuban citizens since the 1959 revolution.
Call for releases
Last December, Mr Roque announced his country's intention to sign up to the two agreements, saying Cuba would allow scrutiny by the recently established UN Human Rights Council in 2009.
One is a covenant on civil and political rights, and the other concerns social, economic and cultural rights.
Previously, Cuba had resisted scrutiny by the UN Human Rights Commission - the predecessor of the Human Rights Council - accusing it of pro-US bias.
It is believed that at least 200 political prisoners are currently being held in Cuba.
Carlos Lauria of the Committee to Protect Journalists in New York called on Cuba to follow up its signing of the covenants and "immediately and unconditionally release the 22 independent journalists currently imprisoned for their work".
"The failure to do so would render its adoption of this important treaty [the UN Bill of Human Rights] meaningless," he added.
Cuban trade unionist Pedro Alvarez and three other Cuban political prisoners were released on health grounds earlier this month, and flown to Spain.
The 60-year-old said that the Cuban authorities had given him the choice to remain in prison or go into exile.
