Frenchman Serge Lazarevic, kidnapped in Mali by Al-Qaeda in 2011, appeared in a video aired on Tuesday by Dubai-based Alaan television urging French President Francois Holland to act to secure his release.
Lazarevic, wearing a black turban, sporting a long beard and flanked by armed men, said the video was being recorded on May 13.
He is the last French hostage worldwide still being held.
The 50-year-old man was kidnapped by Al-Qaeda in the Islamic Maghreb (AQIM) on November 24, 2011, along with Philippe Verdon who was found shot dead in July last year.
He was accompanying Verdon on a business trip when they were seized by a group of armed men at a small hotel in Hombori, in the north, according to his relatives.
AQIM was behind the killing of two French journalists in November.