China's top climate negotiator said on Tuesday a broad deal on carbon markets was possible at the UN COP26 climate talks despite the tensions between Beijing and Washington.

Some delegates say the US-China relationship is crucial for meaningful progress on global climate action at the summit.

It is the first global gathering of leaders to discuss climate change since former president Donald Trump, who antagonised China and quit the 2015 Paris Agreement the meeting is expected to build on, left office.

"China-US joint efforts resulted in the Paris Agreement... it was...