Venezuelan President Hugo Chavez said a mission to pick up three hostages being held in Colombia by Marxist rebels would begin on Friday.
Colombia has given permission for Venezuela's leftist president to send three planes and two helicopters to pick up two female politicians held for years in secret jungle camps and a child born to one of them in captivity.
Chavez told reporters on Thursday night the first aircraft would fly into Colombia on Friday afternoon.
"At approximately 3 in the afternoon the helicopters take off with their crews, one of those with medical equipment. It is the operation's advance party," he said.
Foreign envoys will join the mission, including former Argentine President Nestor Kirchner. They arrived in the Venezuelan capital, Caracas, on Thursday along with relatives of the hostages.
It may take time to complete the mission because of the possibly rough terrain and uncertain weather conditions where the Revolutionary Armed Forces of Colombia, or FARC, are holding the captives.
"The terms of the operation have been agreed upon, but it is still a challenging operation," a senior Colombian military official told Reuters, asking not to be identified.
The FARC is fighting a 4-decade-old insurgency, funded over the past 20 years by the cocaine trade.
Chavez had hoped to have the hostages freed and on Venezuelan soil by late Thursday but the Red Cross said there were logistical and security issues to resolve, and the air convoy was delayed.
"We have gotten the green light from the FARC to take part," said Yves Heller, spokesman in Colombia for the International Committee of the Red Cross. "Now we are working on the logistics."
Early this month, the FARC said it would hand the hostages over to Chavez or someone designated by him.
It would be a diplomatic triumph for Chavez, who launches frequent verbal tirades against Washington.
Colombia's conservative president, Alvaro Uribe, told him last month to stay out of negotiations with rebel leaders who hold hundreds of hostages, but Chavez kept up informal talks and the FARC promised to release the three captives.
Chavez will send the air convoy to the central Colombian town of Villavicencio at the foot of the Andes mountains and then dispatch helicopters to a still unknown meeting point to pick up the captives. They will then go to Venezuela.
Born in rebel camp
The hostages to be released are Clara Rojas, captured during her 2002 vice presidential campaign, former lawmaker Consuelo Gonzalez, snatched the year before, and Rojas' son Emmanuel, fathered by one of her captors.
Emmanuel, aged 3 or 4, has come to symbolize the young victims of Colombia's war in which thousands of people are killed or displaced every year as militias fight over lucrative cocaine-producing land.
His name and the other details of his life under guard in the wilderness were revealed earlier this year by a former police officer who escaped the rebels after eight years in captivity, sometimes in the same camps as Rojas and her son.
The hostages' release could help set the stage for an exchange of other longtime captives, including French-Colombian politician Ingrid Betancourt and three U.S. anti-drug contractors, for guerrillas held in Colombian jails.
The FARC has been pressured by Uribe's U.S.-backed military policies but it still controls wide rural areas and holds about 750 hostages for ransom and political leverage. (Reuters)
Colombia hostage rescue to start Friday -Chavez