West Africa's regional bloc ECOWAS agreed on Sunday to commit 3 300 troops to help recapture northern Mali, part of battle plans that will be sent for United Nations approval by the end of November, the group's chairman said.

The troops would mostly come from Nigeria, Niger and Burkina Faso, but other West African countries and two or three non-African states may also contribute forces, Ivory Coast President Alassane Outtara told reporters in Nigeria's capital.

He said the soldiers could be deployed as soon as the UN approved the military plan, which was drawn up by experts from Africa, the UN and Europe in Mali's capital Bamako last week.

The plan covers a six-month period, with a preparatory phase for training and the establishment of bases in Mali's south, followed by combat operations in the north, Malian army sources told Reuters.

ECOWAS signed off on the latest draft on Sunday but said it still hoped to avoid conflict through negotiations.

"Authority reiterates that dialogue remains the preferred option," said a communique released after the meeting of West African leaders in Nigeria's capital Abuja on Sunday.

"However ... recourse to force may be indispensable in order to dismantle terrorist and transnational criminal networks that pose a threat to international peace and security."

The UN Security Council gave African leaders 45 days from October 12 to draw up a plan for military intervention to retake the north, but diplomats say any such operation is months away.

Once viewed as an example of progress towards democracy in Africa, Mali fell into chaos after a coup in March that toppled the president and left a power vacuum that was quickly exploited by rebels to take over the north.

Foreign powers are divided on the pace of an intervention. Regional powerhouse Algeria says it prefers a negotiated solution, while former colonial master France - which has several citizens held hostage by al Qaeda-linked groups in the Sahara - wants a swift war.

Delegates from Islamist group Ansar Dine are holding talks with regional mediator Blaise Compaore, the president of Burkina Faso, and members of the Tuareg rebel movement MNLA have sought to join efforts to solve the crisis.