Colombian authorities are unsure that leftist FARC guerrillas took a French reporter hostage, President Juan Manuel Santos said, nearly a week since Romeo Langlois went missing.
"I'm not sure whether they have him or not... There are signs, but I cannot be sure that the FARC have him," Santos told reporters in the northern town of Maria La Baja, on Friday.
"If the FARC are intelligent and have half a brain, they would release him immediately, because it is getting more expensive for them to keep him."
Langlois went missing after a firefight on Saturday between security forces and the Revolutionary Armed Forces of Colombia in the south of the country.
A 35-year-old reporter for global television network France 24 who had been accompanying soldiers who destroyed five cocaine production labs in the area, he is believed to have suffered a bullet wound to his left arm.
The military has halted operations in the area where Langlois was kidnapped.
"What happened to him? I do not know," Santos said. "If I were the FARC, I would release him quickly, because this reporter was not a fighter in any way. He cannot be considered a prisoner of war under any circumstances."
A group calling itself the FARC's Front 15 wing, a regional unit made up of about 300 rebel fighters, has claimed responsibility for the abduction in a written message, calling Langlois a "prisoner of war."
But the FARC's central command has yet to make a statement about the journalist.
Military officials have said that after being wounded, Langlois shed his bullet-proof vest and military helmet and surrendered to the rebels, identifying himself as a civilian journalist.
The last French national held by the FARC was Ingrid Betancourt, a former Colombian senator and presidential candidate. She was abducted during her presidential campaign in February 2002, along with her assistant, Clara Rojas.
Betancourt and 14 other hostages -- including three US military contractors -- were freed in an operation by the Colombian military on July 2, 2008.