China has played a "key facilitative role" in promoting this year's UN climate talks on discussing detailed rules for implementing the Paris Agreement, shouldering new responsibilities after the US left a void leaving the pact, according to senior officials and delegates.

"China has played a key role in facilitating dialogues across groups with completely different negotiation interests," Xie Zhenhua, China's special representative for climate change affairs on Saturday, after the climate talks concluded hours later than scheduled time.

He referred to earlier appeals made by developing countries to add pre-2020 actions into official future climate talks agendas, as the Paris Agreement only defines how countries will implement their commitments after 2020.

The onus is on developed nations in pre-2020 actions.

Developed nations present "some levels of flexibility" on improving the roadmap of mobilizing $100 billion per year and review the targets prior to 2020 in the final documents, according to Xie.

Xie said while negotiators have yet to reach agreement on some contentious issues, such as climate financing, this year's outcomes set a good foundation for next year's climate talks.

"China will inject more Chinese wisdom and plans into the global climate governance," Xie said.

A delegate from the Chinese delegation who declined to be named said China has played a different role compared to last year's talks with US withdrawal.

"On some issues China remained quite neutral, so China was able to connect groups with different interests," the delegate said, "The change became more apparent after the US decided to leave the pact. You cannot pin on the US to play such a role."

"On whether China is filling the void left by the US, it's a different issue," the delegate said. "We shoulder different responsibilities for emissions."