African foreign ministers meeting at the African Union headquarters in Ethiopia agreed to write a final operational plan for the African-led force by the end of the month, as well as calling for arms and equipment to be provided for Mali's army from members and international partners.
Kadre Desire Ouedraogo, the president of the Economic Community of West African States, told The Associated Press after Wednesday's closed-door meeting that roughly 3,200 troops would be needed.
Western officials have said the planned African-led military offensive is unlikely to begin before next year - despite growing concern about the terrorist threat militants there pose to the continent and the rest of the world.
The United Nations Security Council passed a resolution earlier this month giving Secretary-General Ban Ki-moon 45 days to help Mali develop a plan to recover the occupied territory. The United States, France and Britain have said they will offer logistical support, but the invasion needs to be led by African troops.
Mali was once considered one of the only stable democracies in West Africa, but it has since plunged into chaos. Islamist groups, including al-Qaida in the Islamic Maghreb, are the de facto rulers of the north.
Ramtane Lamamra, the head of the African Union's Peace and Security Council, said the AU is willing to hold talks with armed groups in Mali if they unequivocally denounce links with terrorists and are willing to forgo their separatist agenda.
Separately, the AU council gave Sudan and South Sudan to reach an agreement on the contested region of Abyei and two weeks on the disputed border areas. South Sudan peacefully broke away from Sudan last year.