Mediators made the announcement Wednesday in Managua.
Ortega made the promise in order to restart talks with the opposition that had been stalled since security forces made more detentions over the weekend.
Luis Ángel Rosadilla, a special envoy to Nicaragua from the Organization of American States (OAS), told reporters that Ortega’s government would release within 90 days “all the people detained and imprisoned in the context” of the protests.
Reports put the total number of people who have been detained in the year since last April’s protests began at more than 700, while at least 325 people have been killed and thousands injured in government crackdowns on protesters.
The opposition had demanded the release of protesters before continuing talks.
Ortega’s government is, in turn, asking that U.S. and European Union sanctions on the country be lifted, according to the BBC.
The United States has imposed sanctions on Nicaraguan officials including Ortega’s wife and Vice President, Rosario Murillo. U.S. national security adviser John Bolton reiterated Wednesday that the U.S. had sanctioned the Nicaraguan oil company Alba de Nicaragua S.A. (Albanisa).
“Efforts by Ortega and his cronies to evade these sanctions will fail,” Bolton wrote.
The opposition group Civic Alliance and Ortega’s government started talks at the end of February for the first time since the summer of 2018.
But after security forces broke up protests over the weekend and detained more than 100 people, the opposition halted talks Monday, saying “dialogue must produce results.”
Demonstrations began in April 2018nitially over cuts to pension benefits and increase rates but spread into general protests against Ortega’s government.
Nicaragua’s economy is suffering from high unemployment and foreign investors pulling out of the country.
Ortega has been in office since 2007 and led the country previously in the 1980s. He has rejected the opposition’s call to move up elections, saying he will serve his full current term until 2021.