Sudan and South Sudan have signed a 'non-aggression' pact over their disputed border following talks in Addis Ababa where African Union-led negotiations between the two sides are being held. Al Jazeera's Harriet Martin, reporting from Khartoum, said that one of the mediators told her there were no expectation of immediate change on the ground, but that the agreement would be a 'means of calling [both countries] to account because they have signed up to the deal'.