"We foresee 3 300 soldiers for a timeframe of one year," Alassane Ouattara, Côte d'Ivoire's president, told journalists after the summit of the 15-nation Economic Community of West African States (Ecowas) in the Nigerian capital Abuja.
The troops would come primarily from Ecowas nations, but possibly from countries outside the bloc as well, he said.
Ouattara said he hoped UN Security Council approval could come in late November or early December, which would allow the force to be put in place days afterward. The plan is to be transferred to the UN through the African Union.
"We have countries that are offering battalions, others companies," he said.
Ecowas countries he named were Nigeria, Senegal, Niger, Burkina Faso, Ghana and Togo.
From outside of Ecowas, "Chad could also participate. We have had contacts with other countries – Mauritania, South Africa."
The summit's final communique stressed that dialogue remained "the preferred option in the resolution of the political crisis in Mali.
"However, regarding the security situation, recourse to force may be indispensable in order to dismantle terrorist and transnational criminal networks that pose a threat to international peace and security," it said.
An Ecowas source had said earlier that regional military chiefs were proposing a total of 5 500 troops, with some 3 200 from the West African bloc and the rest from elsewhere.
It was not clear whether heads of state had rejected the proposal of if the bloc would continue efforts to reach that level.
The final communique urged "member states to concretise their commitments to provide military and logistical contributions to the Ecowas military efforts".
Sunday's summit came as fears grow over the risks the extremists pose to the region and beyond.
A number of African leaders have spoken of the dangers of continued insecurity in the area given the safe haven a continued occupation of Mali's north could provide to al-Qaeda-linked groups and criminal gangs.
However, Ecowas commission president Kadre Desire Ouedraogo has said the bloc should pursue a dual approach of dialogue and military pressure.
The UN special envoy for the Sahel, Romano Prodi, a former prime minister of Italy and ex-president of the European Commission, has said every effort would be made to avoid military intervention.
Some analysts have questioned whether a negotiated solution is possible with Islamist extremists intent on establishing a theocratic state.
Mali rapidly imploded after a coup in Bamako in March allowed Tuareg desert nomads, who had relaunched a decades-old rebellion for independence, to seize the main towns in the north with the help of Islamist allies.
The secular separatists were quickly sidelined by the Islamists, who had little interest in their aspirations for an independent homeland.
They set about implementing their version of strict sharia law, meting out punishments including stonings and destroying World Heritage shrines. – Sapa-AFP