Luis Manuel Diaz, 58, was released on Thursday by the leftist National Liberation Army (ELN) 12 days after he was taken hostage on October 28 in Barrancas, a rural municipality where he lives in the northern province of La Guajira.

Diaz's capture stoked criticism of ongoing peace talks between the ELN and the government of leftist President Gustavo Petro, who is trying to put an end to Colombia's six-decade internal conflict that has left more than 450,000 dead.

The government and the ELN began a six-month ceasefire in August.

"My aspirations are to continue in my town because I have my entire family in my town," Diaz said at a press conference.

"The government has given me impressively strong and great support. I trust and have faith that it will provide me security to be in Barrancas."

The kidnapping underscored the lack of control that the ELN's top brass exerts over their rank and file, according to analysts and security sources.

Diaz on Friday offered details of his captivity, during which his kidnappers advised him to remain calm, he said.

"A lot of quite difficult horseback riding, lots of mountains, rain," Diaz said, recalling "almost 12 days without sleep."

"Even though the treatment was good, I didn't feel very comfortable," he said.

The ELN, made up of 5,800 members, including some 2,800 combatants, is considered a terrorist organization by the United States and the European Union.

The rebel group is accused of financing itself through kidnapping, in addition to drug trafficking, illegal mining and extortion.

On Friday, the group's top commander, Antonio Garcia, said on social media that the peace negotiations did not prohibit kidnappings as a means of financing.