Central African Republic crisis: Djotodia future in balance
Central African Republic (CAR) interim leader Michel Djotodia is expected to face pressure to step down at a regional summit under way in Chad.
His failure to quell violence between Christian and Muslim militias has prompted speculation that he may quit.
However, some CAR officials say his resignation is not on the agenda at the summit in neighbouring Chad.
Seleka rebels staged a coup last March, installing Mr Djotodia as the country's first Muslim leader.
The then-President Francois Bozize, from CAR's majority Christian population, was forced into exile and the country has since descended into chaos.
The UN has warned of an impending humanitarian disaster.
Ahmat Allami, Secretary-General of the 10-nation Economic Community of Central African States (ECCAS), said that members of the Central African Republic's National Transitional Council (CNT) had been flown in at short notice to the Chadian capital N'Djamena to decide the leadership of their nation.
"No-one can speak on behalf of the Central Africans. That's why we have asked the CNT and representatives of political parties to come to N'Djamena to decide on the future of the transitional institutions," Mr Allami was quoted by Reuters as saying.
Mr Allami said earlier that "regime change" was not the goal of the meeting.
A source close to Mr Djotodia quoted by the Reuters said that CAR leaders had run out of patience with him.
"It's finished for him now," said the source.
However, his spokesman told the BBC he would not be stepping down.
The BBC's Paul Wood in Bangui says that if he does resign, the effects would be unpredictable - it could take the steam out of the conflict, or trigger a power struggle engulfing the country in its worst violence yet.
French officials said the summit would discuss various options for continuing the transition, including allowing the president of a National Transitional Council to take over or mandating Prime Minister Nicolas Tiangaye to run the country until elections.
Although Mr Djotodia has officially disbanded the Seleka rebels, he has proved unable to keep them in check.
Their brutal actions have prompted Christians to form vigilante groups, sparking a deadly cycle of revenge attacks.
The AU has some 4,000 peacekeepers in the country and France has deployed 1,600 troops to try to end the violence.
More than 1,000 people have died in the past month alone and the number displaced has more than doubled, to nearly a million.
On Wednesday, the UN warned that measles had broken out at the airport in the capital, Bangui, where about 100,000 people are seeking refuge from clashes.
The UN says about half the population of Bangui - more than 500,000 people - have been driven from their homes and 2.2 million people are in need of humanitarian assistance.