The National Sovereign Inclusive Dialogue (DNIS) forum -- boycotted by opposition members, two out of three leading armed rebel groups and civil society organisations -- also ratified Deby's right to run for president post-transition.

The national forum began its work in August after multiple delays.

It wrapped in N'Djamena on Saturday, before a packed audience of civilians and military, with a speech by General Deby.

The junta leader promised "a new phase of the transition" devoted to "achieving the prescribed deadlines for the return to constitutional order".

Deby took over in April last year after his father, Idriss Deby Itno, the country's iron-fisted ruler for 30 years, was killed during a military operation against rebels.

He had vowed to hand back power to civilians after 18 months, a deadline that would run out this month.

Deby also pledged to Chadians and the international community that he would not run in the upcoming presidential elections.

After coming to power, the junta of 15 generals scrapped the constitution, dissolved parliament and dismissed the government.

The international community had urged Deby not to extend the transition beyond 18 months, and not to run for president in the eventual elections.

However, in June last year, the junta leader dealt a first blow to those hopes, floating another 18 months of transition "if the Chadians do not manage to reach an agreement" on the way forward.

A week ago the DNIS adopted "by consensus" a raft of resolutions including prolonging the transition period to 24 months.

Chad, one of the world's poorest countries, has endured repeated uprisings and unrest since gaining independence from France in 1960.

Deby, in military uniform, saluted the crowd as he arrived in an SUV, surrounded by bodyguards sporting red berets.

At the end of a ceremony lasting more than two hours, he expressed his "pride" at the forum meetings which he said have made it possible to "get out of the horror scenario".

Deby reiterated his commitment to releasing prisoners of war in exchange for a ceasefire and their participation in national dialogue.