United States climate envoy John Kerry voiced hope on Friday that Beijing and Washington would work together more closely on the climate emergency after they struck a pact to accelerate action against greenhouse gas emissions.

Speaking at a forum in Singapore, the former secretary of state emphasised cooperation -- even as the rivals spar over other flashpoint issues such as Taiwan.

"I hope that our working together will increase the sharing of data, increase the sharing of options and begin to engage us in a very important dialogue with the top leadership of both of our countries," Kerry said at the Bloomberg New Economy Forum.

"China agreed to work with us to lay out an ambitious -- and those are the words -- ambitious national action plan, which China must submit and begin acting on by COP 27, a year from now," he added.

In addition to cutting methane and carbon dioxide emissions, the US-China plan announced in Glasgow will also see the world's two biggest polluters looking to improve measurement and mitigation in the fossil fuel, waste and agriculture sectors, though the deal has been criticised for lacking specifics.

US special climate envoy John Kerry has touted the US-China climate deal as an opportunity for Beijing and Washington to work closely together
US special climate envoy John Kerry has touted the US-China climate deal as an opportunity for Beijing and Washington to work closely together AFP / Paul ELLIS

Earlier this month, around 100 nations joined an initiative to cut methane emissions by at least 30 percent this decade, but China was noticeably absent.

Methane is considered the second key greenhouse gas after carbon dioxide. While it can be naturally released and absorbed by the earth, its emissions have skyrocketed with industrialisation and the expansion of agriculture.

Kerry described methane reductions as "the single biggest, fastest grab that we can make for dealing with this problem".

The US has said it plans to be carbon neutral by 2050, while China has set a net-zero target for 2060 with coal consumption to peak at 2030.

But Beijing has yet to spell out precisely how it intends to achieve these goals, and environmentalists have warned that China can essentially keep increasing emissions until 2030.

The agreement between China and the US came as a surprise on the sidelines of the COP 26 climate summit, and it will see the world's top two economies setting up a working group and meeting regularly.