Some 1,600 French troops have been deployed in CAR to work alongside 4,000 troops from African countries
The UN believes at least 10,000 troops will be required in any force sent to end unrest in Central African Republic, the French UN envoy says.
Ambassador Gerard Araud described the situation in CAR as "very, very dire".
His comment comes after the UN Security Council approved a resolution allowing European troops to use force in CAR.
About a million people - 20% of the population - have fled their homes during months of religious violence, after rebels seized power last March.
Speaking to reporters, Mr Araud said the African Union force in the country, intending to reach 6,000 troops, "is considered now too low because frankly the situation is very, very dire and the country is huge"
