France has been very interested in Colombia's hostage crisis since Betancourt was kidnapped while campaigning for the Colombian  presidency in 2002.

 

Earlier this week Colombia said it wanted Sarkozy to become involved in helping resolve the impasse in talks to swap some 45 hostages, including Betancourt and three Americans, for some 500 Farc prisoners held by Colombian authorities.

 

Personal involvement

 

Sarkozy said in his televised message: "For my part, I pledge to remain personally involved in the search for a humanitarian solution, for the liberation of all the others being held. Moreover, I promise to redouble efforts, if that is desired, to contribute to finding a way out of the Colombian conflict.

"But at this moment, Mr Marulanda, a woman in danger of dying must be saved. I have a dream: to see Ingrid among her family this Christmas.

 

"Mr Manuel Marulanda, you can make this dream come true, you can  save this woman, you can show the world that Farc understands human  imperatives.

 

"Mr Marulanda you bear a heavy responsibility. I urge you to assume it."

Last week, the Colombian government released excerpts from rebel videos of the hostages, sparking a public outcry over their plight.

 

One clip showed Betancourt gaunt and despondent at a rebel hideout.

 

Direct talks

 

Sarkozy's statement came after Luis Carlos Restrepo, Colombia's peace commissioner, proposed direct talks with the rebels on Tuesday.

 

"I am willing to go wherever the Farc wants," he said.

 

Restrepo said Farc had yet to provide a list of names of men they wanted released [EPA]

"We are responding to national and international clamour and it is time for this drama to end ... this is a priority."

 

Restrepo made the offer of talks before heading for a meeting with Sarkozy to invite a French delegate to join the negotiations.

 

Restrepo said Alvaro Uribe, the Colombian president, had asked him to finalise an agreement to exchange Farc prisoners for hostages.

 

Restrepo said Bogota had prepared a decree to enact legal procedures to free jailed rebels once an agreement was reached, but that the rebels had yet to provide a list of names they wanted included in any deal.

Sarkozy has been urging Uribe to engage in hostage negotiations and has expressed concern over Betancourt's health.

A source close to Sarkozy said he "does not want to rush through every door that opens ... We must find the right approaches".

Uribe recently removed Hugo Chavez, the Venezuelan president, as a mediator in talks with Farc.

A diplomatic spat erupted after Uribe accused Chavez of violating agreed protocol and Chavez froze relations with Colombia.