China has called on Sudan and South Sudan to resolve a dispute that has blocked the flow of oil exports from the south.

Beijing purchases nearly five percent of its total oil imports from South Sudan.

A Chinese foreign ministry spokesman on Tuesday urged the two Sudans to exercise “restraint” and use a “flexible and pragmatic approach” to settle their differences.

Landlocked South Sudan relies on its northern neighbor’s pipelines and port on the Red Sea to export oil.

Sudan said it halted South Sudan’s oil exports because the newly independent south owes $730 million in transit fees.

South Sudan has said Khartoum is charging transit and customs fees so high they amount to “economic war.”

South Sudan took control of about 75 percent of Sudanese oil when it became independent July 9.

The two countries still are negotiating terms for sharing oil revenues. They also have not resolved which side will control the oil-rich Abyei region on the border.