Beijing on July 21 said climate cooperation with Washington will depend on the overall strength of Sino-US relations, after US climate star John Kerry urged China to curb emissions quickly.

Sino-US tensions have soared in recent months and tackling climate change is among a handful of issues where the two sides have agreed to work together.

However, after Kerry called on Beijing to act more rapidly on climate challenges, Chinese Ministry of Foreign Affairs spokesman Zhao Lijian warned that cooperation on environmental issues could be affected by deteriorating Sino-US relations.

“I want to emphasise that the cooperation between China and the United States in specific fields is closely related to the overall health of Sino-US relations,” Zhao told a press briefing on July 21.

“The US should not wantonly interfere in China’s internal affairs to the detriment of China’s interests, while demanding China’s understanding and support on bilateral and global affairs.”

Kerry on July 19 called on Chinese policymakers to ensure emissions peak before the targeted deadline in 2030 since it was “the only way to break free from the world’s current mutual suicide pact”.

The goal of limiting global warming to 1.5 degrees Celsius was “essentially impossible” without “sufficient reduction by China”, he said during a policy speech in London.

Kerry visited Shanghai in April as he looks to cooperate on climate change despite friction on other fronts.