John Kerry, the top U.S. climate diplomat, intends to step down after more than three years relentlessly pressing countries to get more aggressive in the fight against global warming, according to people with knowledge of the matter.

The former U.S. secretary of state, senator from Massachusetts and Democratic presidential nominee will transition to a role outside the federal government in coming weeks, said the people, who asked not to be identified because the announcement wasn’t public.

Kerry, 80, plans to help the re-election campaign of U.S. President Joe Biden, Axios reported. The White House didn’t comment on the development. The State Department declined to comment.