Sudan on Wednesday denied Chadian accusations it was supporting dissidents trying to oust President Idriss Deby and said an African Union summit would go ahead in Khartoum in January.
Chadian army dissidents launched two attacks against the Chadian border town of Adre last week and the Chadian government said they chased the rebel back into the neighbouring Sudanese Darfur region, where they say the rebels have bases.
Deby on Tuesday said Sudan was helping the rebels prepare a fresh attack in the coming days.
"This is nonsense -- he is just trying to draw attention away from the internal problems he is having," said Sudan's State Minister for Foreign Affairs al-Samani Wasiylah.
"This is a mutiny in the army, everyone knows that, and we don't want to be involved in that," he told Reuters.