Australia will provide two military aircraft to help UN peacekeeping efforts in South Sudan as the country edges closer to civil war.

Acting prime minister Warren Truss says Australia will respond to a United Nations request to provide two aircraft to aid in the conflict.

The two-week mission involving the C-17A Globemaster and C-130 Hercules aircraft may involve moving military personnel and evacuating some of the 45,000 civilians endangered by the outbreak of further hostilities.

“We trust that this mission will be relatively brief, that it will be able to make a constructive contribution to this United Nations force and a peaceful return to South Sudan just as soon as possible,” Mr Truss said.

No additional personnel other than aircraft crew will be deployed, he said.

Mr Truss urged Australians to leave the country, adding that commercial air services are still available.

“We would encourage Australians still in South Sudan to make urgent arrangements to leave the country to make sure they are not caught up in the kind of violence that has been occurring over recent days,” he said.

Seventy Australians in South Sudan have registered with the mission, many of whom are personnel from non-government organisations.

But the government believes there are up to 1000 others, many of whom are dual nationals, who have not registered with Australian envoys.

Mr Truss says the mission’s aim is to ensure the South Sudan government can operate effectively and provide for its people long term without need for a continuing United Nations presence.

“That’s our objective and that’s why we’ve been prepared to be involved in this new initiative,” he said.

Hundreds of people have died in violent clashes throughout South Sudan, which gained independence from Sudan in 2011 after more than two decades of brutal civil war.