Colombia's ELN rebels freed hostage ex-lawmaker Odin Sanchez on Thursday, the government confirmed, clearing the way for peace talks next week.
In a message on Twitter, the ELN -- Colombia's last active rebel group -- called on the government to now free two of its fighters and fulfill a deal between the two sides to set up negotiations on ending a conflict that began in 1964.
"The ELN's humanitarian committee fulfilled its word by handing over Mr Odin" to the Red Cross, the rebels said.
"We are now waiting for our two pardoned members."
Sanchez, who had been held captive since April 2016, was handed over in the remote jungle region of Choco in western Colombia.
The government confirmed his release.
"Odin Sanchez is now with the humanitarian commission and will leave minutes from now in a helicopter bound for Quibdo," the regional capital, it said.
The two rebels set to be released in exchange -- Nixon Cobos and Leivis Valero -- are to be handed over in the mountains of Santander, in the northeast.
President Juan Manuel Santos, who won the Nobel Peace Prize last year, is trying to end a more than half century conflict that has killed more than 260,000 people and left 60,000 missing.
His government is currently implementing an historic peace deal with the country's largest rebel group, the Revolutionary Armed Forces of Colombia (FARC).
Talks with the ELN, or National Liberation Army, were due to open last October, but broke down when the rebels refused to release Sanchez.
Under the new agreement, the talks are now set to open Tuesday in the Ecuadoran capital, Quito.