A mission is under way to pick up two high-profile hostages due to be released by Colombia's Farc rebels.
Clara Rojas has been held hostage since 2002
The hostages are former Congresswoman Consuelo Gonzalez and Clara Rojas, an aide to former Colombian presidential candidate Ingrid Betancourt.
Two Venezuelan helicopters have taken off from a Colombian town on their way to an undisclosed location in the south-east of the country, reports say.
A similar rescue attempt was called off last month.
It ended amid recriminations between the rebels and the Colombian government, and was a huge embarrassment to Venezuelan President Hugo Chavez, who helped broker the deal.
It now seems Mr Chavez has pressured the guerrillas to deliver the two hostages, says the BBC's Jeremy McDermott in Colombia.
The helicopters, emblazoned with the logo of the International Committee of the Red Cross (ICRC), which is overseeing the operation, took off from the town of San Jose de Guaviare.
Mr Chavez said on Wednesday that he had received the co-ordinates of the location where Ms Rojas and Ms Gonzalez would be handed over.
The Colombian government responded quickly, with the Peace Commissioner Luis Carlos Restrepo saying they would "provide all the necessary guarantees" to enable the hostages to return home as soon as possible.
The families of the hostages are again daring to hope
The Farc had promised to release the women, along with Ms Rojas's three-year-old son, in December.
The Farc accused the Colombian government of sabotaging the hostage release by continuing military operations in the area.
The government countered, saying the rebels backed out of the deal because they no longer held the young boy, Emmanuel, who was found living in a foster home in Bogota.
On Wednesday, Defence Minister Juan Manuel Santos said he had ordered military operations to be suspended in the area where the hostages were expected to be freed.
"We are so, so happy to know that, God willing, tomorrow Clara and my mother will be free again after so much time," Ms Gonzalez's daughter, Patricia Perdomo, said on Wednesday.
Ms Gonzalez was kidnapped in 2001. Ms Rojas was seized in 2002, while she and Ms Betancourt were out campaigning.
Ms Betancourt, a French-Colombian citizen, is still in captivity.
She is one of some 45 high-profile hostages who are considered "exchangeable" and who it is thought that the rebels would release in return for the government freeing hundreds of jailed rebels.
It is believed the guerrillas hold about 750 hostages in total, some for political leverage but many for ransom.