Colombian President Juan Manuel Santos reshuffled his cabinet on Monday in what he said was preparation for a looming peace deal to end a half-century conflict with armed rebels.

"This will be the cabinet of peace... of the post-conflict phase," he said in a speech.

"For that reason it will be composed of people from all regions and all political leanings."

After more than three years of peace talks, the government and the Revolutionary Armed Forces of Colombia (FARC) say they are close to signing a deal but have yet to agree on disarmament and ratification of the final accord.

The prospect of a transition to peace raises difficult questions about justice and accountability for killings and disappearances during the decades of conflict.

The key post of justice minister in the new cabinet went to a relatively neutral political figure: Jorge Eduardo Londono of the minority centrist Green Party.

The reshuffle also brought in new ministers of labor, industry and housing, among other posts.

The half-century territorial conflict in Colombia has claimed the lives of more than 260,000 people. It has drawn in left- and right-wing guerrillas and paramilitary groups, as well as government forces.

Santos has also launched efforts to begin peace talks with another left-wing guerrilla group, ELN.

Despite the progress, Santos's popularity has reached an all-time low. He was reelected in 2014 for four years.