The mediator, a member of Colombian for Peace involved in talks with the Revolutionary Armed Forces of Columbia, known as FARC, did not reveal the reason for the postponement, Colombia Reports reported Sunday.
The hostages' release was rescheduled from March 30 and April 1, the mediator said.
A delegation is to go to Brazil Saturday to meet with Brazilian Air Force personnel in charge of providing helicopters and personnel for the hostage release. The following day, the delegation and helicopters will fly to Villavicencio, a city in central Colombia, where the two release operations will take place.
FARC announced in December it would release the hostages.