The seventh round of peace talks for Sudan's troubled Darfur region have been postponed, but it is not clear when they will resume.
The African-Union sponsored talks were due to begin in the Nigerian capital, Abuja, Monday. African Union officials are quoted as saying the delay could range from several days to an indefinite postponement.
AU spokesman Nureddin Mezni told the French News Agency, AFP, the talks were postponed because of logistical reasons.
The last round of talks ended in October with little progress amid escalating violence in Darfur and infighting within Darfur's main rebel group.
Saturday, a senior U.S. official, Assistant Secretary of State for African Affairs, Jendayi Frazer, met with rival leaders of the rebel Sudan Liberation Army to urge them to present a united front at the next round of peace talks.