China calls for improved dialogue to eliminate "misunderstandings" that haunt an important oil investment by China National Petroleum Corporation in South Sudan, the Foreign Ministry said on Thursday.

On Tuesday, South Sudan reportedly expelled Liu Yingcai, the head of Petrodar, the main oil firm operating in the new African nation, and a consortium mainly of CNPC and Malaysian oil and gas company Petronas.

Foreign Ministry spokesman Hong Lei said China and South Sudan base their cooperation on mutual respect, equality and reciprocal benefits, and this has brought "tangible and substantial benefits" to the peoples of both countries.

"We hope the related parties can improve their communication, and eliminate misunderstanding for the sake of long-term cooperation," Hong said.