A West African military force assembled to intervene against Islamic radicals in Mali is ready to be deployed as soon as the United Nations issues a green light, a senior official at the centre of the preparations claimed Tuesday.

"The military force is fully ready. Once the UN gives the go-ahead, deployment can start immediately," Kadre Desire Ouedraogo told journalists here.

Ouedraogo, a former prime minister of Burkina Faso, is the president of the commission, or permanent secretariat, of the 15-nation Economic Community of West African States (ECOWAS).

His comments contradicted the scepticism expressed by some military experts on the readiness of ECOWAS to send in a force capable of sweeping Islamists out of northern Mali, a vast desert area that has fallen under the control of Al-Qaeda-linked militants.

ECOWAS leaders meeting in Nigeria agreed on Sunday to deploy a force of up to 3,300 men. A detailed plan of action, backed by the African Union, is due to be presented to the UN by the end of the month and Ivory Coast President Alassane Ouattara has said deployment could come as soon as early December.

Ouedraogo said the full force would not necessarily be deployed at once.

"That will not be a classical war, there will be special operations and it will be done in phases," he explained.

The African force being assembled will have logistical support from France and the United States, who have been lobbying hard to get ECOWAS to take action and to ensure Algeria does not stand in their way.

"We have requested air support and all our partners have promised their support," Ouedraogo said.

Doubts about whether the mooted intervention will go ahead have been fuelled by the ambiguous stance adopted by Algeria, the biggest military power in the region.

Algiers reacted to Sunday's ECOWAS declaration by saying that it believed negotiations with the rebel groups in northern Mali -- who are mostly led by Algerian nationals -- could still deliver a settlement.

Ouedraogo said Algeria had indicated it would not stand in the way of military intervention and, in that case, would close its border with Mali, which measures around 1,700km (1,100 miles), in order to try and deny militants an escape route.

The ECOWAS official appeared sceptical about the chances of a negotiated settlement.

"Any political dialogue will be with groups who recognise the unity of Mali and the secular character of the state," he said. "There will be no discussions with terrorist or mafia groups."

The Islamists in northern Mali have imposed a strict version of sharia law in the areas under their control, which has led to cases of unmarried couples being stoned, thieves having hands amputated and suspected drinkers being whipped.