Spokesman Sean McCormack called on Beijing to use the appointment to convince the Sudanese government to drop its resistance to allowing a UN-mandated and led peacekpeeping force into Darfur.
"We would hope they use every bit of their leverage with the Sudanese government to convince them that it's the right thing to do, it's in everybody's interest, that the UN force be allowed to get into Darfur," he said.
|More than 200,000 people have died and 2.5 |
million have been displaced in Darfur [EPA]
The announcement came after a group of US politicians demanded China step up efforts to persuade Sudan's government to stop the violence in Darfur.
In a letter to the Chinese president they warned that without action on Sudan the Olympics could become a disaster, rather than the image enhancer Beijing is expecting.
The Chinese appointment also comes in the wake of an Amnesty International report this week claiming that China and Russia were breaching a United Nations arms embargo by letting weapons into Sudan.
Both countries denied the allegations.
Commenting on the appointment of the new envoy a Chinese foreign ministry spokeswoman said it reflected Beijing's hope to "solve the issue by political means".
"We are ready to make joint efforts with the international community, including the US," Jiang Yu said.
She said that for the foreseeable future the special representative would focus on Darfur because the situation there had "drawn significant international attention".
China, a veto-wielding permanent member of the UN security council, buys two-thirds of Sudan's oil exports and has sold the country weapons and military aircraft.
It has blocked efforts to send UN peacekeeping forces to Darfur without Sudanese consent, drawing criticism for not using its influence to do more to stop the Darfur crisis.
Calls from human rights groups for a boycott of the 2008 Olympics have drawn an angry reaction from Beijing.
Last month, China's assistant foreign minister said anyone who advocated such a move would have to be "either ignorant or ill-natured".