Dialogue is the "preferred option" to resolve the crisis in Mali, a UN envoy said Tuesday, even though West African nations have agreed to send troops to wrest control of the country's north from Islamists.

"All options and avenues of dialogue should be exploited to try to fix the problem in a peaceful manner," Said Djinnit, the UN's representative in West Africa, told journalists after meeting Burkina Faso President Blaise Compaore, who is also chief regional mediator in the crisis.

Djinnit said the point of the meeting was to examine "how we can ensure that dialogue is fruitful and brings results quickly".

While not ruling out talks, leaders from the 15-nation Economic Community of West African States (ECOWAS) meeting Sunday in Abuja agreed to send 3,300 soldiers to retake control of north Mali, which has been occupied by Islamists since April.

The blueprint for a military force would be transferred to the UN Security Council via the African Union.

Djinnit said he "cannot speak about the deadline for the deployment" of the force.

But he stressed that "the option preferred by everyone, including ECOWAS, the African Union and the United Nations, is the option of dialogue, and we hope that dialogue will take place as soon as possible."

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 and set about implementing their version of strict Islamic law, meting out punishments including public stonings and floggings and destroying World Heritage sites they considered idolatrous.