West African army chiefs have adopted a military plan to expel Islamist rebels controlling northern Mali, as one extremist group pushes for a negotiated solution to the crisis.

Mali has slid into chaos since a March 22 coup overthrew the government of president Amadou Toumani Toure, creating a power vacuum that enabled Islamist rebels to seize the vast desert north.

The military blueprint, reached at a meeting of army top brass in Bamako that wrapped up late Tuesday, will next be studied by regional heads of state for approval before being presented to the UN Security Council on November 26.

"We are very satisfied," Malian army chief Ibrahim Dembele said at the close of the meeting.

"On the whole, the strategy was adopted (and) friendly troops will come here to help Mali reconquer the north."

The details of the plan as adopted by the military chiefs have not been made public.

The UN wants clarification on the composition of the proposed force, the level of participation from the various west African nations, the financing of the operation and the military means to carry it out.

"It is an ambitious plan, we should expect a little over 4,000 people in case of military intervention. We have studied all the parameters, now we await instructions from our heads of state," said an officer from Benin who attended the meeting.

Presidents from the Economic Community of West African States (ECOWAS) will study the plan during an upcoming meeting in Abuja, a source close to the meeting told AFP.

"I really hope things will advance. We must not release pressure on the terrorist groups, everyone must be convinced," Guinean General Sekouba Konate -- who is in charge of the standby force -- told AFP.

On Tuesday Ansar Dine, one of the groups occupying the vast arid zone, called for all armed movements to halt hostilities and join in peace talks.

The occupation of an area larger than France by Islamists linked to the north African Al-Qaeda branch has triggered fears in the region and among Western powers that the zone could become a haven for terrorists.

Ansar Dine (Defenders of Faith, in Arabic) along with the Movement for Oneness and Jihad in West Africa (MUJAO) have implemented an extreme form of sharia in cities they control, stoning, whipping and amputating transgressors.

-- Ansar Dine 'talking the talk' --

However Ansar Dine said Tuesday it "rejects all forms of extremism and terrorism" after meeting the chief regional mediator, Burkina Faso President Blaise Compaore.

They urged "all the armed movements" to follow their lead with the aim of establishing "an inclusive political dialogue."

US State Department spokeswoman Victoria Nuland said Washington welcomed "Ansar al-Dine's announcement rejecting extremism and declaring the group's willingness to engage in a process of honest political dialogue."

The group was saying "good things about the possibility for political reconciliation with the transitional government," she said.

"So they're talking the talk. Now they need to walk the walk and work on an actual reconciliation deal that others can join into as well."

German Foreign Minister Guido Westerwelle meanwhile said allowing a terrorist refuge in northern Mali would threaten global security.

Westerwelle, whose country has said it will support any military operation in the African country, held talks with UN Secretary General Ban Ki-moon and UN Security Council ambassadors on Mali and Syria at UN headquarters.

"The destabilization of the north of Mali is a very important issue for the whole world, especially for Europe," he said.

A "safe haven for terrorists" in northern Mali "would be a threat to the security of the whole world, especially of the neighbors," Westerwelle added.

"We have to stabilise the north of Mali, and it is necessary to support the Mali government in the south. There are a lot of measures which we are considering at the moment but it is too early to decide now."

Burkina Faso's Foreign Minister Djibrill Bassole, a key mediator in the Malian crisis, joined calls for Ansar Dine to turn words into actions and "refrain from unnecessary provocations."

He stressed that the Islamist group had made no reference to the issue of Islamic law.

In Bamako, where interim authorities have struggled to assert authority, politicians were favourable to negotiations with the Islamists.

"Territorial integrity is non-negotiable but from the moment that Malians decide to lay down arms and come to the negotiating table, we are available to listen if they are really sincere," said Makan Diarra, presidential adviser.

Bineta Diakite of the Malian Democratic Alliance, the party of transition leader Dioncounda Traore, said the members of Ansar Dine "are our brothers."

"If they want to talk, why not listen to them? But we are not going to talk this time and wait for another rebellion in one month or two years," she told AFP.

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