The African Union and United Nations are working to appoint a joint chief mediator to jumpstart efforts to bring peace to Sudan's Darfur region, UN Darfur envoy Jan Eliasson said on Monday.

The former Swedish foreign minister, who is also working on a new diplomatic initiative for Darfur, said the selection process was in its final stages.

"Our job was to re-energize the political process," he said in Khartoum, where he was on a visit for talks with Sudanese officials.