Sunday's statement from the president was in response to a video request from ELN leader Antonio García, who said the guerrillas tax cocaine trafficking in areas they control, but said the ELN is not involved in the operation.
The ELN has been accused of close collaboration with drug cartels in both the production and transportation of cocaine.
Leftist President Petro, a former member of Colombia's guerrilla movement, responded on X that he agrees with the ELN's request for an independent investigation.
At the same time, he appealed to guerrillas to support replacing coca cultivation with other crops.
