Colombian President Gustavo Petro on Friday designated new commanders for the military and the police, saying he chose the officials because they have not been accused of corruption or human rights violations.

Colombia's security forces have a long history of corruption scandals and human rights abuses committed during the country's nearly six decades of conflict.

Petro, a critic of Colombia's military establishment and ex-member of the M-19 guerrillas, has promised profound changes to security forces and urged the new officials to protect life.

The criteria for selecting the new commanders was "zero corruption, zero violation of fundamental rights," Petro said during a news conference.

"The concept of human security means that success lies not in the number of dead, but in substantially reducing deaths, massacres and increasing substantially peoples' liberties and rights," Petro added.

His government heralded a change in mentality and strategies, Petro said, with enemy death tolls ceasing to be a reason for the promotion of security personnel.

The president named General Helder Fernan Giraldo as commander of the armed forces, General Luis Mauricio Ospina to direct the army and Vice-Admiral Francisco Hernando Cubides to head the Navy.

General Luis Carlos Cordoba will direct the Air Force and General Henry Armando Sanabria the national police.

Petro pledged during his campaign that soldiers accused of human rights violations will stand trial in regular courts, rather than military ones.

He has also promised to remove the police from the defense ministry and dismantle its ESMAD riot squad, which recently came under international criticism for its role in protester deaths.

The Andean country's internal armed conflict of almost 60 years left around 450,000 dead between 1985 and 2018 alone.

Petro has said the drug war is a failure and called during his inaugural speech this week for a new international strategy to fight trafficking.