Chad's military government and dozens of opposition groups started peace talks on Sunday in Qatar as a first step towards ending a rebellion and holding elections.
The landlocked African nation was thrown into turmoil by the killing of longtime leader Idriss Deby Itno in battle with rebels in the country's north last April.
His son, Mahamat Idriss Deby Itno, took over the country after his death, fronting a 15-member military junta and vowing to hold free elections, according to AFP.
Chad's Prime Minister Albert Pahimi Padacke and African Union Commission head Moussa Faki Mahamat told the opening of the conference that both sides would have to make "concessions" for the talks to succeed.
But the process risks being protracted and complicated.
Some 44 armed rebel and opposition groups were invited to the Doha meeting -- though some were missing at the opening, which had already been delayed from February 27.
Diplomats said these "precursor" talks could take weeks and that a planned "national dialogue" due to start on May 10 may have to be delayed.
Under the younger Deby's plan, the dialogue would be a prelude to agreeing on a new constitution and then holding elections.
Chad has a long history of volatility since gaining independence from France in 1960 and tens of thousands have died in various conflicts.
It has a large and shifting constellation of armed opposition groups.
"The situation in Chad is very serious, we have to deliver this," the African Union's Faki said in his address to the government and armed groups.
Padacke said that "peace requires more courage and maturity than war".
"Real courage does not mean brandishing your weapon but to have the courage to lay it down", added the prime minister.
He also said success in the talks would help stabilize the whole Sahel region where radical Islamist groups have staged regular attacks.
Libya's Foreign Minister Najla al-Mangoush also said that the peace process would be crucial to improving stability and help "fight terrorism" in the Sahel.
As a condition for the Doha talks, Chadian rebels called for a general amnesty and the release of "prisoners of war" and the return of confiscated assets.
The military government says it has released hundreds of prisoners and amnestied several prominent leaders.
