Colombia President Ivan Duque reiterated on Thursday his call for ELN Marxist rebels to release hostages as a prerequisite to restarting suspended Cuban-hosted peace talks.
Duque said he would only speak to the guerrillas if they "suspend all criminal activities" and agree to "demobilize, disarm and reinsert" into civilian life.
But the starting point for that is "the liberation of hostages."
"We cannot legitimize violence as a mechanism to put pressure on the state," said Duque during a press conference with Spain Prime Minister Pedro Sanchez.
The ELN, the last recognized rebel group fighting government forces since the 2016 peace accord with FARC guerrillas, said two weeks ago it was prepared to release the nine hostages: four military, three police, and two civilian contractors.
But since then they have failed to agree with the government on the security protocols to carry out the handover.
Peace talks have been on hold since August 1 after Duque's predecessor Juan Manuel Santos admitted defeat in his bid to agree a disarmament plan with the ELN before his mandate came to an end.
The nine hostages were captured after those talks concluded.
Duque has promised a more hardline approach to the ELN and after his inauguration he said he would take a month to decide whether or not to resume rebel talks.
"These 30 days expire on September 7," said Duque. "We've analyzed it and have seen worrying acts of violence.
"Kidnappings, extortion, terrorist attacks, which obviously demonstrates everything but a genuine desire for peace."
The ELN, or National Liberation Army, has around 1,500 guerrillas and an extensive support network.