The African Union's chairman Thomas Boni Yayi has called for Nato to send forces to Mali to help fight militant Islamists who have captured the north.
The Malian conflict was an "international question" and Nato should intervene just as it had done in Afghanistan, Mr Yayi said.
However, the campaign against the militants should be led by an African force, he said.
The UN last month approved plans to send some 3,000 African troops to Mali.
UN officials said they did not expect the force to be deployed before September.
Mr Yayi, who is Benin's president, called for Nato intervention after talks with Canadian Prime Minister Stephen Harper in Ottawa.
"Nato should play a part and the African force would lead the way as was done by Nato in Afghanistan," he said.
"This is an international situation."
Nato took command of the international peacekeeping force in Afghanistan in 2003.
Several Nato members, including the US and France, say they will help to train an African force for the Mali operation, but have not offered to send ground troops or launch air strikes.
Mr Harper said Canada - a Nato member - was not considering direct military involvement in Mali.
"Obviously we are very concerned about the situation, and the development of essentially an entire terrorist region is of grave concern to everybody in the international community," he said.
The Islamists and Tuareg rebels seized power in northern Mali - an area the size of France - in the chaos following a coup in the capital, Bamako last year.
Their ranks had been bolstered by fighters from Libya, who crossed into Mali after the overthrow of Colonel Muammar Gaddafi's government in 2011.
A Nato bombing campaign helped Libya's militias to oust Col Gaddafi's government.
The alliance between the Islamists and Tuareg groups quickly collapsed, with the Islamists taking the region's main urban centres.
The Islamist groups have since destroyed ancient shrines in Timbuktu and imposed a strict interpretation of Islamic law, sparking international outrage.
Burkina Faso's government is trying to mediate an end to the conflict.
It is due to host talks between the Islamists, Tuareg rebels and the Malian government in the Burkinabe capital, Ouagadougou, on Friday.