President Omar Hassan al-Bashir of Sudan and South Sudan President Salva Kiir reached the agreement Saturday at a meeting in Addis Ababa, Ethiopia, The New York Times reported.
Both side said they would carry out the terms of a September agreement, in which they said yes to withdrawing forces from the border. Neither side has pulled away from the border yet; instead they accuse each other of supporting rebels in and near the border region.
On Saturday, the African Union mediator, former South African President Thabo Mbeki, said Bashir and Kiir agreed to "create the safe demilitarized border zone" and carry out "the existing agreements unconditionally."
The demilitarized zone will be roughly 6 miles wide.