Preparations are accelerating for an intervention in Islamist-occupied northern Mali as West African leaders prepare to adopt a military blueprint this weekend before seeking UN approval.

Facing a potentially violent ouster, one of the extremist groups, Ansar Dine, which has occupied key cities such as Timbuktu for seven months, has called for dialogue and a halt to hostilities.

However plans for military action have not slowed.

Ex-Guinean transitional leader General Sekouba Konate, who is supervising preparation, met chief regional mediator Burkina Faso's President Blaise Compaore Thursday to discuss "the juxtaposition of the military intervention and the ongoing dialogue," a source in the president's office told AFP.

While some have presented the military intervention as a fait accompli, divisions still remain on whether it is the best solution.

The UN special envoy for the Sahel, Romano Prodi, said Thursday it was "a last resort" after talks with Algerian President Abdelaziz Bouteflika.

Algeria, with its superior military capabilities and its 1,400-kilometre (875-mile) border with Mali, is seen as key to any military operation but it favours a negotiated solution instead.

"We still have the chance to work for peace," Prodi was quoted as saying by the APS news agency.

Ansar Dine spokesman Mohamed Ag Aharid on Wednesday warned in Ouagadougou that any military intervention in Mali would "set the region ablaze."

As both war and dialogue remain on the table, the Red Cross said in Geneva Thursday that some 500,000 people could no longer sustain themselves in north Mali amid security risks, food shortages and the breakdown of political structures.

Once the military blueprint is approved by leaders from the Economic Community of West African States (ECOWAS), meeting in Abuja on Sunday, a statement said, it "will then be transmitted through the African Union, before November 15, to the UN Security Council."

The Security Council on October 12 approved a resolution urging ECOWAS to speed up preparations for a military intervention to help recapture northern Mali.

The council -- which asked for clarification on the composition of the proposed force as well as financial and military means -- is expected to give the green light for the deployment of troops once it has studied the plan.

-- Arrest of alleged jihadist from France --

The military strategy was drawn up with the help of experts from the European Union, AU, UN and the region and adopted by ECOWAS army chiefs on Tuesday.

The details of the plan have not been made public, but army sources say over 4,000 troops could be sent into Mali.

In Paris, the French Defence Ministry said foreign and defence ministers from five European countries -- Germany, Poland, Spain, Italy and France -- will meet on November 15 to discuss a European mission aimed at training Malian troops.

The mission could include 200 soldiers and begin in January, an aide of French Defence Minister Jean-Yves Le Drian said.

Mali, once one of the region's most stable democracies, rapidly imploded after a coup 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 sharia law.

Ansar Dine (Defenders of Faith) and the Movement for Oneness and Jihad in West Africa (MUJAO) have cracked down on local populations, stoning unmarried couples, amputating thieves' hands and whipping drinkers and smokers.

The crisis has displaced about 200,000 Malians inside the country, while as many have fled to neighbouring states, according to the UN.

The Islamists' ties with Al-Qaeda in the Islamic Maghreb (AQIM), which has long been present in Mali's north, have triggered fears in the region and the West that the zone could become a haven for extremists.

Regional security sources have warned that French citizens or Africans living in Europe are attempting to sign up with the jihadists.

A jihadist described as "French-African" who was arrested Tuesday in the centre of Mali allegedly seeking to join the armed extremists has been identified by France as Ibrahim Aziz Ouattara.

A French judicial source said Ouattara, born in France in 1988, had been charged in 2010 in connection with a planned attack against the head of a Paris mosque. He has travelled to Yemen and Pakistan and was arrested in Egypt in 2010 before being sent back to France.

A source close to the investigation in Mali reported he was travelling on false documents and freely expressed his wish to "die a martyr."