On the same day, the US government notified Congress that it will remove the now-defunct FARC guerrilla group, which lay down arms after the deal, from its official terror group designation.

November 24 marks five years since the government and Marxist guerrillas of the Revolutionary Armed Forces of Colombia (FARC) signed deal to end Latin America's longest-running internal conflict.

Guterres accompanied Colombian President Ivan Duque on a visit Tuesday to Dabeiba, a mountainous, rural municipality in the northern Antioquia department to see first-hand "the achievements of peace."

He visited a reintegration facility at Llano Grande, where several former FARC combatants live with their families, seeking to rejoin civilian life by learning new skills.

"Every day they renew their commitment to build a country in peace. They know better than anyone that peace is not built overnight. This requires effort, tenacity, to build and preserve," said the UN Secretary General.

Some 13,000 guerrillas have surrendered their arms since 2016, but violence persists in many regions of Colombia where FARC dissidents, who reject the peace deal, continue to fight paramilitary and rebel groups and drug traffickers in the world's largest cocaine producer.

Nearly 300 former FARC fighters have been killed in the last five years.

- 'Enemies of peace' -

"Unfortunately, there are enemies of peace," Guterres warned, calling for the rights of ex-combatants, civic leaders and human rights defenders to be guaranteed.

"We need to redouble our efforts to ensure the sustainability of (reintegration) projects with technical and financial support, land and housing," he said.

Guterres met former FARC fighters, including Rodrigo Londono -- known by his war name Timochenko -- who assured the UN chief that "despite the fact that nearly 300 signatories (of the peace accords) have been killed, we remain committed to the road taken five years ago."

In another step towards normalization, the US government which backed Bogota in its war against the FARC, on Tuesday informed Congress it would remove the group, since transformed into a minority political party, from its terror list, a congressional source told AFP.

Such a listing, since 1997 for the FARC, allows Washington to impose financial and diplomatic sanctions against target groups.

State Department spokesman Ned Price said the peace process in Colombia was "something that we have sought at every step of the way to preserve."

The conflict resulted in nine million people being either killed, disappearing or being displaced, according to authorities.

On November 24, 2016, after negotiations in Cuba, the fearsome guerrilla group laid down arms and signed a deal with then Colombian president Juan Manuel Santos.

But the terror label has continued to hang over former FARC members.

The peace deal "set Colombia on a path to a just and lasting peace. So we remain fully committed to working with our Colombian partners on the implementation of the peace accord," said Price.

On Wednesday, Guterres will attend an official ceremony in Bogota at the Special Jurisdiction for Peace (JEP), a judicial body created by the 2016 agreement to investigate crimes and atrocities committed during the conflict.

Colombia is experiencing its most violent period in years due to continued fighting between armed groups for control of drug fields, illegal gold mines and lucrative smuggling routes.