BEIJING (AFP) - Chinese President Xi Jinping and his US counterpart Barack Obama discussed the Paris climate summit - where talks have been running through the night - in a phone call on Friday (Dec 11), Beijing's foreign ministry said.

Without giving direct quotes, a statement on its website cited Xi as saying that China and the US "must strengthen coordination with all parties" and "make joint efforts to ensure the Paris climate summit reaches an accord as scheduled".

A deal would be beneficial to the international community, it cited him as adding.

The ministry cited Obama as replying that the US was willing to maintain coordination with China, again without giving direct quotes.

Xi and Obama both attended the UN summit's opening ceremony on Nov 30.

A deal has yet to be reached at the gathering, but sleep-starved envoys tasked with saving mankind from catastrophic climate change aim to wrap up a historic accord on Saturday after a second all-night session of talks, the French hosts said.

China and the US are the world's two largest carbon emitters, though China is estimated to have released nearly twice as much as the United States and around two and a half times the European Union.

The Asian giant pledged last year to peak carbon dioxide output by "around 2030" - suggesting at least another decade of growing emissions.

"We still have some distance to cover before reaching our final deal, and some key issues remain unresolved," said foreign ministry spokesperson Hua Chunying Friday (Dec 11).

"Developed countries should play the leading role and make greater efforts," she said, while calling upon all participant countries to "show their flexibility" and "narrow differences."