ADDIS ABABA  - The African Union has endorsed a plan for military intervention in Mali, where Islamists have seized control of its desert north, the AU's Commissioner for Peace and Security said Tuesday.

The AU Peace and Security Council "has decided ... to endorse a harmonised concept of operations for the planned deployment of AFISMA, which is the African-led mission in support of Mali," Ramtane Lamamra told reporters, speaking after an AU peace and security meeting in the Ethiopian capital Addis Ababa.

Lamamra did not provide details of the mission, but said it aims to "regain the occupied regions in the north of the country, dismantle the terrorist and criminal networks and restore effectively the authority of the state over the entire national territory."

He said the AU urged the United Nations to "authorise for an initial period of one year the planned deployment" of the force.

West African leaders at an emergency summit in Abuja on Sunday approved a 3,300-strong force for Mali to wrest control of the north from Islamist extremists as fears grow over risks they pose to the region and beyond.

Lamamra said he believes the UN will pass a resolution approving the mission before the end of the year, but did not confirm when the first troops could be deployed.

The troops are expected to come from members of the 15-nation Economic Community of West African States (ECOWAS), but also possibly from countries outside the regional bloc as well, according to Lamamra.

"There can be room for troops that would be contributed by non-ECOWAS countries, African non-ECOWAS countries, so there is some flexibility on that," he said.

Mali 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 and set about implementing their version of strict Islamic law, meting out punishments including stonings and destroying World Heritage shrines.