KINSHASA, Congo (AP) — Mediators in Congo say they won't make a Christmas deadline to resolve the country's political impasse.

The announcement Saturday comes after representatives held overnight talks until 5:30 am. in an effort to reach an agreement.

On Friday, the opposition had expressed new optimism, saying a working document would have President Joseph Kabila remain in power but only until an election in 2017. The presidential majority says it thinks elections in early 2018 are more likely.

The political dispute has raised fears of widespread unrest in this vast Central African nation. Already at least 40 people have died in violence in the past week, the U.N. says.

Kabila has been in power since 2001 and is barred from running again. Critics accuse him of delaying elections to extend his rule.