"We hope to rescue and liberate them in the coming hours," Chavez said when addressing troops in Caracas on Friday.
The captives are Consuelo Gonzalez, a former congresswoman, Clara Rojas and the boy, believed to be the son of Rojas and a rebel fighter, born three to four years ago.
Chavez, who has dubbed the mission Operation Emmanuel after the boy, said the move had been delayed as Farc rebels had not informed him of the exact location.
The MI-172 helicopters are being sent by special arrangement with the Colombian government.
International observers are flying with the group, including representatives from France, Switzerland and several Latin American countries.
Oliver Stone, the American film director, and Nestor Kirchner, a former Argentinian president, were also part of the mission.
Luis Carlos Restrepo, Colombia's primary peace negotiator, said that his government gave the mission its full support and would not allow its military to interfere.
Restrepo will join the committee in Villavicencio, 95km east of the capital Bogota, from where they will be given instructions for movements on Saturday.
The group will disperse and head to a number of potential meeting points given by Farc before being told which is the final destination whilst in the air.
The handover is expected to take place on Saturday or Sunday.
Mariana Sanchez, Al Jazeera's correspondent in Caracas, said that there could be complications.
|Royas was kidnapped in 2002 and has |
given birth to a boy since [AFP]
"There is a deadline of 72 hours that the Colombian government has imposed, for Sunday 7pm local time (1200GMT Monday).
"Once the helicopters land the hostages may not be there, the helicopters and committee may be sent to a second or a third location. They may even have to travel after they land.
"President Hugo Chavez said that he does not know about this deadline. The Colombian government says it is a deadline requested by the Venezuelan government."
Secrecy of the handover point has been paramount to Farc, who distrust the Colombian government they have been fighting them for more than four decades.
Rojas was kidnapped more than six years ago when working as an aide to Ingrid Betancourt, a former Colombian presidential candidate. Gonzalez was abducted in 2001.