0432 GMT September 24, 2022
UN Secretary-General Antonio Guterres and the African Union urged the junta and opposition to seize the latest opportunity to stabilise a country considered key to international efforts to stamp out extremists in the Sahel region, AFP reported.
But after five months of mediation efforts by Qatar, the main rebel Front for Change and Concord in Chad (FACT) announced hours before the ceremony at a Doha hotel that it would not sign the deal.
Under the agreement, Mahamat Idriss Deby's Transitional Military Council and hundreds of opposition representatives will launch a national peace dialogue in the capital N'Djamena on August 20.
Deby, who was in Doha for the signing, took power after the death of his father, long-time president Idriss Deby Itno, in a battle with rebels in April last year.
The dialogue aims to agree the schedule and rules for a presidential election that Deby has promised by October.
However, few of the groups who took part in the talks, or the diplomats who monitored the painstaking negotiations, expect an election this year.
Chad, one of the world's poorest countries, has endured repeated uprisings and unrest since its independence in 1960.
Deby promised a national dialogue and elections within 18 months of him seizing power, but the mediation has been fraught with discord.
FACT and other opposition groups have demanded that he announce that he will not stand in the election. Deby has said this can only be negotiated in N'Djamena.
He has also said his transitional rule could be extended but faces pressure from the international community to keep the deadline.
In a video message to the ceremony, UN Secretary General Antonio Guterres called the signing "a key moment for the Chadian people" but said the national dialogue had to be "inclusive" to be successful.
African Union Commission chief Moussa Faki Mahamat said that both sides keeping their promises would be "crucial criteria" to build trust with the Chadian people.