The troops had been expected to depart on Saturday, but Nigeria's Foreign Minister Olu Adeniji said: "Obviously there have been some delays, logistical problems with transportation. Definitely, our troops will leave on Monday."
AU spokesman Assane Ba confirmed the deployment and said that further details would be given at a press conference on Sunday on the margins of the Sudanese peace talks in the Nigerian capital Abuja.
The troops are to head to el-Fasher in northern Darfur to join a 150-strong Rwandan unit, also under AU command, protecting 133 unarmed observers overseeing a ceasefire signed on April between rebels and government forces.