Bishop Roland Alvarez was sentenced to 26 years in prison after refusing to join other political prisoners in exile.

Bishop Rolando Alvarez, an outspoken critic of Nicaraguan President Daniel Ortega, was sentenced to 26 years in prison last Friday over charges of “conspiracy” and “fake news”.

“We condemn this action by the government of Nicaragua and urge Bishop Alvarez’s immediate release,” US State Department spokesperson Ned Price told reporters on Monday, adding that last week’s prisoner release was a welcome step but “not a panacea for the many concerns we have with the Nicaraguan regime”.

Ortega’s government has been accused of silencing dissent and jailing critics like Alvarez, the bishop of the central city of Matagalpa. Alvarez had been under house arrest since August when police raided his church residence in a pre-dawn raid.

Alvarez has criticised the Ortega regime for violence that has left hundreds dead in the wake of antigovernment protests that erupted in April 2018. The bishop also has condemned what he considers police harassment against himself and others in the Catholic Church, calling what he endured “persecution”.

Ortega, meanwhile, has previously denounced the Catholic Church as a “dictatorship” and has accused bishops and priests of being “coup plotters” working on behalf of the US. Church leaders had been among the mediators in the 2018 conflict.

On Sunday, Pope Francis expressed concern over Alvarez’s lengthy prison term, one of the longest handed down to an opposition figure in recent years.

“The news that arrived from Nicaragua has saddened me no little,’’ the pope said in an address at St Peter’s Square in the Vatican, asking for those involved to “open their hearts”.

Alvarez was one of two political prisoners on Thursday who refused to board a plane to the US after the Nicaraguan government freed them on the condition that they be expelled from the country.

Ortega’s government has described the release as an effort to eject criminals and foreign “agents” from Nicaragua.

The 222 individuals who were released included five rival presidential candidates, journalists, priests, student activists and other critics of Ortega’s government. Ortega’s allies in the legislature moved to strip all the prisoners of their Nicaraguan citizenship after they left the country, an act that would require a constitutional change to become official.

US Secretary of State Antony Blinken spoke over the phone with Nicaraguan Foreign Minister Denis Moncada last Friday, during which the two discussed the prisoner release and the “importance of constructive dialogue”.

The US has previously instituted a series of sanctions against the Nicaraguan government, which it has criticised as authoritarian.