California Governor Gavin Newsom is due to announce a moratorium on executions and a temporary reprieve for all 737 inmates on death row in the state.
US media report he plans to sign an executive order later on Wednesday, describing the death penalty as "inconsistent with our bedrock values".
California has not carried out any executions since 2006, as a series of court battles over execution methods have been waged.
No death row inmates will be released.
https://www.bbc.com/news/world-us-canada-47549422