The UN Security Council will vote on a measure authorising thousands of African and French troops to end anarchy in the Central African Republic, where massacres have led to warnings of genocide-style strife.
The resolution, which envoys say is certain to be passed unanimously on Thursday, also orders an arms embargo against the huge, impoverished nation where chaos has reigned since rebels forced the president to flee in March.
Muslim and Christian groups are fighting each other and tens of thousands of people have taken refuge in churches and mosques fearing sectarian attacks, according to aid workers.
The draft resolution highlights the "total breakdown in law and order" in the state which, it adds, risks "degenerating into a countrywide religious and ethnic divide, with the potential to spiral into an uncontrollable situation."
The council will give an African force a 12-month mandate to restore order. French troops will have permission to use "all necessary measures" to support the African contingent.
There are about 2500 troops in the African-led International Support Mission in the Central African Republic (MISCA) that will eventually reach 3600 and on December 19 become an African Union force.
France has 600 troops there and plans to increase this to 1200.
But United Nations leader Ban Ki-moon has warned that up to 9000 troops could be needed if the crisis blows up and a full UN force has to take over.
Violence has worsened in the country of 4.6 million people since the Seleka coalition of rebels forces deposed president Francois Bozize in March.
An interim government led by a former rebel has since lost control. The massacre of 12 Muslim women, children and men this week by suspected Christian radicals highlights the need for "urgent" action, according to French UN envoy Gerard Araud.
"The French forces and the African forces will act as quickly as possible. We need the resolution that will be passed tomorrow, events show how crucial it will be," Araud said.
