France recently sent a mission to Colombia to try to secure the release of the Franco-Colombian hostage Ingrid Betancourt, President Nicolas Sarkozy said during a visit to Libya.

"We sent people to negotiate, two people," the French president told reporters late Wednesday on the sidelines of his talks with Libyan leader Moamer Kadhafi.

Sarkozy said the mission, sent after he took over as president mid-May, returned without formal proof that Betancourt, a former Colombian presidential candidate kidnapped by Colombian rebels in February 2002, was still alive.

"We want proof that Ingrid is alive, and we don't have that. We have some elements, but we want some real proof of life."

Following the release of six foreign medics in Libya, Sarkozy vowed France would press ahead with efforts to free Betancourt from the rebel Revolutionary Armed Forces of Colombia (FARC).

"I will not abandon Ingrid Betancourt, French diplomacy will not abandon her," Sarkozy said.

"Barely a day goes by when we are not working on this," said the French president, who said he advised Colombian President Alvaro Uribe against any attempt to releases the hostages by force.