John Kerry, who has been working as President Joe Biden’s special climate envoy for about three years, plans to step away from that role to help the president’s reelection effort, several outlets reported Saturday.

The former secretary of state and presidential candidate believes Biden’s reelection to be essential in the war on climate change, according to Axios, which was the first to report the news.

Kerry, 80, met with Biden on Wednesday to inform him of his intention to resign, The Washington Post and others reported.

The Post said he will likely tout Biden’s work on climate change along the campaign trail. 

Kerry helped the administration steer discussions at three United Nations climate summits in Scotland, Egypt and Dubai. Last month, at the most recent conference, nearly 200 countries agreed together for the first time to transition away from fossil fuel usage.

Kerry was a key engineer of the 2015 Paris Agreement, which saw nearly 200 countries pledge to reduce harmful emissions and collectively address the effects of climate change. 

Former President Donald Trump, in contrast, has insisted that climate change is not a real problem. He withdrew the U.S. from the Paris Agreement during his presidency; Biden re-joined on his first day in office.