Mara Salvatrucha and Barrio 18 (also known as M-18, Calle 18) street gangs in Honduras signed a truce this week, after decades of bloodshed.
The “zero crimes, zero violence” deal was signed in a ceremony at Sampedrano prison in the northern city of San Pedro Sula.
The city had the world's highest homicide rate last year with 169 murders per 100,000 residents.
Leaders of MS-13 and Barrio 18 spoke to reporters from prison cells about reducing violence in the country.
"Our truce is with God, society and authorities. We ask society and authorities to forgive us for the damage we have done," said an MS-13 member.
Both MS-13 and Barrio 18 are the two largest gangs in the country and were formed by inmates who had been deported back to Central America from the United States for crimes.
The peace treaty was brokered by Bishop Romulo Emiliani and Adam Blackwell, secretary for multidimensional security at the Organization of American States.
The truce had been months in the works and was modeled on a similar agreement between gangs in El Salvador last year, which saw massive declines in crime and violence.
GlobalPost analysis: Will El Salvador's gang truce hold?
"They want to reconcile with Honduran society and ask for forgiveness from the Honduran people, and I think it is a step forward," said Emiliani.
"What is coming is difficult. It is not easy. It is complicated."
Honduran President Porfirio Lobo congratulated those involved and said the government would endorse the plan.
Honduras is one of the most dangerous countries in the world and has one of the highest homicide rates.
It is considered a transit point for cocaine destined for the US.