A new UN peacekeeping mission to be deployed in the Central African Republic next month must be backed up by political talks to restore stability, the head of the force said Tuesday.

Some 1,800 fresh troops will be arriving in CAR on September 15, joining 5,800 African forces already serving in the country to launch the UN mission known as MINUSCA, said Babacar Gaye.

"My main asset is not only to have troops, but to have a comprehensive approach for the protection of civilians and the stabilization of the country," Gaye told reporters after briefing the UN Security Council.

"An important part of this comprehensive approach is the political process."

There are about 2,000 French troops serving alongside the African forces in CAR, which has been engulfed in sectarian violence since a March 2013 coup ousted Francois Bozize.

Months of fighting between mainly-Muslim Seleka rebels and mostly-Christian militias in the country has left thousands dead and forced around a million people from their homes.

The country's first Muslim prime minister, Mahamat Kamoun, was named as part of a bid to bring the ex-rebels back into the political mainstream, but a Seleka spokesman said this month they would not join the government.

"The road will be long," Gaye told the 15-member council. "The situation is very worrisome."

The chief of the mission, who is also Secretary-General Ban Ki-moon's special envoy to CAR, said the authorities in Bangui must form an inclusive government that will lead the country toward elections.

At least 34 people were killed in a string of attacks last week in villages in northern CAR attributed to former Seleka rebels, the latest upsurge of violence that threatens to derail a ceasefire signed in late July.