THE UN Security Council has unanimously backed sending up to 12,600 international troops and police to take over from French and African forces battling Islamist guerrillas in Mali.

The United Nations is aiming for a July 1 start by the new force, but the 15-nation council will decide later whether the conflict has eased enough for the handover.

French troops moved into Mali in January to halt an Islamist advance on the capital Bamako and have since forced the al-Qaeda-linked militants into desert and mountain hideouts.

France is to keep up to 1000 troops in Mali and they will maintain responsibility for military strikes against the Islamists, who are now waging a guerrilla campaign.

UN resolution 2100 authorises France to intervene if the UN troops are "under imminent and serious threat and at the demand" of UN chief Ban Ki-moon.

The resolution authorised the new force to use "all necessary measures" to stabilise major cities, protect civilians and help the government extend its authority over the vast West African nation.

"The adoption of this resolution confirms the unanimous international support for the stabilisation of Mali and France's intervention," said France's UN envoy Gerard Araud.

Mali's Foreign Minister Tieman Hubert Coulibaly called the resolution "an important step in the process to stem the activities of terrorist and rebel groups".

The proposed UN Multidimensional Integrated Stabilisation Mission in Mali, to be known by its French acronym MINUSMA, would have a maximum of 11,200 soldiers and 1440 police.

Mali's army launched a coup in March 2012, which unleashed the chaos that allowed Tuareg rebels and their erstwhile Islamist allies to take over the north of the country and impose a brutal Islamic rule.

Many shrines in Timbuktu and other cities were destroyed, and public executions and amputations staged.