Addis Ababa - Chad's president Idriss Deby took over the post of African Union chairperson on Saturday, replacing Zimbabwean President Robert Mugabe.
"I accept this task with pleasure, but with a little agony as the responsibility you entrust in me is heavy and fraught with challenges," Deby said, in speech at AU headquarters in Ethiopia.
He told fellow presidents that conflicts across the continent had to end.
"Everything that we are doing now will be in vain and without purpose if we allow Africa to go through these perpetual crises: South Sudan, Libya, Somalia, Burundi, the Sahel, the Lake Chad basin," Deby said.
"Through diplomacy or by force... we must put an end to these tragedies of our time. We cannot make progress and talk of development if part of our body is sick. We should be the main actors in the search for solution to Africa's crises."
Deby, 63, one of Africa's longest ruling presidents, emerged as the leader of the arid north-central African state in December 1990, after the war which ousted the regime of Hissene Habre.
Mugabe, Africa's oldest president aged 91, has held the ceremonial role for the past year, welcomed his "brother" Deby to the post.
"Whatever support you want from me, I will still be there, until God says come, then I'll go and join the others," Mugabe said. "But as long as I am still alive, I will still have the punch."
The one-year presidency which rotates between different regions of the continent.