Freed hostage Ingrid Betancourt spoke on Sunday through a radio broadcast to those still being held in the Colombian jungle by leftist guerrillas, urging them not to lose hope.

The Franco-Colombian politician was freed on Wednesday by a Colombian army operation after more than six years in the hands of the Revolutionary Armed Forces of Colombia (FARC). She arrived in France on Friday to a hero's welcome.

"I have spoken to French President Nicolas Sarkozy several times and he committed himself publicly to continue the fight for all the hostages who are still in the jungle," Betancourt told remaining captives of the FARC during her broadcast, of which snippets were aired on French media.

She spoke from Paris on Radio Caracol, a Colombian radio station routinely used to communicate with FARC hostages, on which she had listened to messages from relatives and supporters during her long captivity.

A source close to Betancourt said she had urged the jungle captives not to lose hope and that they too would soon taste freedom.

Betancourt has been in back-to-back media interviews, medical tests and official functions since she arrived in France. She told the newspaper Le Journal du Dimanche she would return to Colombia in a few days, giving no further details.

French radio station Radio France Internationale (RFI) said in a statement Betancourt would send another message to the hostages on Monday to offer further support.

Her children, Melanie and Lorenzo, had broadcast messages to her on RFI when she was in the jungle.

"I have left behind human beings who are still in the hands of the FARC. So I still need you (France) because we cannot leave them where they are," Betancourt told the Journal du Dimanche, echoing comments made to Sarkozy in public on Friday.

The 46-year-old Betancourt, who had appeared gaunt and depressed in a video released in late 2007, has seemed in surprisingly good health since she came out of the jungle on Wednesday. She had medical tests in a Paris hospital on Saturday.

"Like me, the doctors are very surprised because of course there are traces of everything I experienced, but their conclusion is that the body resists many things extraordinarily well," she said in her interview with the Journal du Dimanche.

She also told the paper she wanted to write a play about her ordeal.