In a joint statement, the two countries agreed to back a new global renewables target and work together on methane and plastic pollution, just weeks until Cop28 starts in Dubai.
The joint statement also said that US climate envoy John Kerry and his Chinese counterpart, Xie Zhenhua, agreed to "revive a bilateral climate working group" that will discuss areas of co-operation between the two countries.
It will focus on key areas including cutting methane emissions, boosting efficiency and the "circular economy", and exchanging information on policies and technologies to reduce emissions.
The two sides also promised to work together to curb forest loss and plastic pollution, Reuters said.
The move is a boost for global climate efforts with just weeks to go before Cop28 starts in Dubai. The news was welcomed by the presidency.
“The consensus reached between the US and China is a significant moment ahead of Cop28," said Dr Sultan Al Jaber, Cop28 President, on Wednesday.
"It clearly signals that despite global challenges, Cop28's call for climate action is uniting parties and raising ambition.
"I look forward to welcoming the US and China to Cop28, and all parties as we look to deliver a historic outcome.”
Both the US and China, who are also the world's biggest emitters, said they support a declaration by G20 leaders to triple global renewable energy capacity by 2030, and also agreed to "accelerate the substitution for coal, oil and gas generation", Reuters reported.
The joint statement said they anticipate "meaningful" reductions in emissions from the power sector this decade, although it did not go into details about fossil fuels
Reuters reported that both sides also agreed to include methane in their 2035 climate goals – the first time China has made such a pledge – and committed to advancing "at least five" large-scale co-operation projects in carbon capture, utilisation and storage by the end of the decade.
The joint statement comes as the presidents of the two countries prepare to meet in California.
Climate talks between the two had been marred by tension since former House of Representatives speaker Nancy Pelosi visited Taiwan in 2022.