Kerry has been instrumental in brokering a number of international climate agreements.

The former secretary of state and senator has been pushing for climate change solutions within the Biden administration and will now help him in publicising the president’s work on the issue, media reported on Saturday.

Officials said Kerry announced his resignation to Biden on Wednesday, and his staff learned of the decision on Saturday, sources familiar with the situation told Reuters news agency. He is set to step down in the coming months.

Most recently, Kerry represented the US at the COP28 UN climate summit in Dubai, and in a show of rare unity, worked with China to help negotiate a historic albeit watered-down agreement to transition away from oil, gas and coal.

The US and China are the world’s two largest polluters, accounting for 41 percent of greenhouse gas emissions.

As climate envoy, Kerry aimed to maintain close diplomatic ties with China on climate change even as numerous other tensions between Washington and Beijing have simmered.

A month before the summit, which took place from November 30 to December 13, 2023, Kerry welcomed his Chinese counterpart Xie Zhenhua to draft an outline of climate action that partly served as the basis for the nearly 200-nation Dubai deal.

Kerry has led the US delegation at three UN climate summits.

Shortly after beating former President Donald Trump, one of Biden’s first moves in office in 2021 was to rejoin the Paris climate agreement, which Trump had exited.

Under that 2015 UN deal, which Kerry also helped broker, countries committed to limiting the Earth’s warming to “well below” 2 degrees Celsius (3.6 degrees Fahrenheit).

In an interview with Reuters in December after COP28, Kerry said he would continue working in climate advocacy.

“I will continue as long as God gives me the breath and work on it one way or the other,” Kerry said.