Story highlights Alan Gross is not among those who will be pardoned

Cuban President Raul Castro says prisoners from 25 countries will be freed

The move shows the "generosity and strength of the revolution," he says

The president cites the pope's upcoming visit as a motivation for the release

Cuba will pardon more than 2,900 prisoners, the government said Friday, though U.S. subcontractor Alan Gross is not among those who will be freed.

The decision to release the prisoners follows "numerous requests" from their family members and religious institutions, and is a humanitarian gesture, said Cuban President Raul Castro.

Among those who might be freed are prisoners over the age of 60, along with those who are sick, female or young with no previous criminal record. With some exceptions, prisoners convicted of spying, terrorism, murder and drug trafficking will not be released.

Those who will be freed have already served a "important" part of their sentences and exhibited good behavior, according to an official statement published on the state-run website Cubadebate.

The jailed American, Gross, will not be among those pardoned, the Cuban Interests Section in Washington said.

Gross was jailed in December 2009, when he was working as a subcontractor on a U.S. Agency for International Development project aimed at spreading democracy. Castro has accused him of importing satellite equipment to connect dissidents to the Internet, and this year Cuba's highest court upheld the 15-year sentence imposed on Gross for committing crimes against the security of the state.

He has maintained his innocence and said he was trying to help connect the Jewish community to the Internet.

Castro, speaking to the National Assembly, said that 86 prisoners from 25 countries would be among those released in coming days.

He cited the upcoming visit of Pope Benedict XVI as one of the motivations behind the move, which he said showed the "generosity and strength of the revolution."

The pope has said he plans to visit Mexico and Cuba before Easter.

In 2010, Castro agreed to free prisoners arrested during the 2003 crackdown on political dissidents. The Caribbean nation has released many of them, as well as other prisoners jailed for "counterrevolutionary" activities, ranging from hijacking to arson.